Sizing Guide

Measure Twice, Order Once

To ensure a precise and comfortable fit, it is important to take accurate measurements. Please follow these guidelines

If you would prefer an easier way to measure, we offer a full sizing kit that includes rings, tubes and a shaft length tool.  If you have your own 3d printer, the STLs fro all the sizing pieces are available at https://makerworld.com/en/@hzdgrip

Measure carefully The sizing kit is your best option for correct measurements.  If you don't want the sizing kit, use a flexible measuring tape, calipers, or a piece of string for the most precise results.  There are 2 basic measurements that are needed and 2 optional measurements available with custom devices.

• Shaft Diameter
• Glans Ring Diameter
• Shaft Length (Optional)
• Glans Length (Custom Only)

 

A few helpful tips before you begin

✔ Take multiple measurements at different times of the day to account for natural fluctuations.

✔ Do not pull or stretch the penis while measuring—keep it in its natural resting state.

✔ Ensure a snug but not tight fit when wrapping the measuring tape or string around the shaft.

✔ Do not base your measurements on other devices or measurements used for other devices.  The Grip is unique in its design and other styles of measuring may not provide a proper fit.

All Measurements are based on flaccid states

 

Measuring the Shaft Diameter

This measurement ensures the shaft cage fits securely around your shaft without being too tight or too loose.  You want the shaft cage to be somewhat fitted.  It should not be so tight that you need any lubrication to put it on.  

It's a little harder with the o-rings, but they will get you close.

 

If you are an extreme grower you may find sizing up one or two millimeters to be beneficial.  It may also be helpful to measure both flaccid and erect.  The shaft size should fall somewhere between your flaccid size and erect size.  In general it should be within 1 or 2mm of your flaccid size

Method 1: Sizing Rings or O-Rings (Preferred)

For the shaft, you want the o-ring that is snug but not overly compressing. You don't want it loose or to have room where it just slides on and off with no effort. You also don't want it clamping down and creating an indention on your shaft. When you have a ring that you need to pull on, won't fall off when you let go and isn't squeezing your shaft, then you are probably at the correct size.

Method 2: Using a Measuring Tape (Not recommended)

1. Ensure your penis is fully flaccid.
2. Wrap a flexible measuring tape around the middle of the shaft to get the circumference. 
3. Record the circumference in millimeters (mm) or inches.  You want the measurement to be snug without compressing the shaft
4. Calculate the diameter by dividing the circumference by π (3.14).
5. Round to the nearest whole number
6. Example: If your circumference is 100mm, your diameter is 100 ÷ 3.14 = 31.8mm. Rounded up to 32mm

Method 3: Using a String (Not recommended)

1. Ensure your penis is fully flaccid.
2. Take a piece of non-stretchable string or thin strip of paper.
3. Wrap it around the middle of the shaft where the measurement is needed.
4. Mark the point where the string overlaps itself.
5. Lay the string flat and use a ruler to measure the length from the start to the marked point.  This is the circumference
6. Calculate the diameter by dividing the circumference by π (3.14).
7. Round to the nearest whole number

Example: If your circumference is 100mm, your diameter is 100 ÷ 3.14 = 31.8mm. Rounded up to 32mm

Measuring the Glans Ring Diameter

his measurement ensures the glans ring fits securely without being too tight or too loose. For proper function, the glans ring must be smaller than 82% of the shaft diameter.

The ideal range is typically 73–75% of the shaft diameter, but individual anatomy can require going slightly above or below that range.

Method 1: Sizing Rings or O-Rings (Preferred)

For the glans you want a snug fit. If you don't have to pull the glans through the ring with some effort it is probably too big of a ring. If you are using the sizing rings, you can use the small tab to simulate the pressure of the clamp.  Place the tab at the bottom of the glans and then pull it forward. If the ring pulls off without too much effort then you are too big. If the ring holds tight and your glans starts to turn towards the ceiling you are pretty close to the correct size.  

If you are using an o-ring, you can perform the same test by threading a piece of string through the o-ring. move the string to the bottom of the glans and pull forward. If the ring pulls off without too much effort then you are too big. If the ring holds tight and your glans starts to turn towards the ceiling you are pretty close to the correct size. 

Method 2: Using a Measuring Tape (Not recommended)

1. Locate the area directly behind the glans (where the shaft meets the head).
2. Wrap the measuring tape around this area or use calipers to measure across.
3. Record the circumference and divide by π (3.14) to find the diameter.
4. Round up to the nearest whole number
   
   Example: If the circumference is 90mm, the diameter is 90 ÷ 3.14 = 28.6mm. Rounded up to 29mm

Method 3: Using a String (Not recommended)

1. Wrap a piece of string around the area immediately behind the glans.
2. Mark where the string overlaps.
3. Measure the length of the string with a ruler.
4. Record the circumference and divide by π (3.14) to find the diameter.
5. Round up to the nearest whole number

Example: If the circumference is 90mm, the diameter is 90 ÷ 3.14 = 28.6mm. Rounded up to 29mm

Shaft Diameter	Suggest Glans Ring Diameters
24	15, 16, 17, 18, 19
25	16, 17, 18, 19, 20
26	17, 18, 19, 20, 21
27	18, 19, 20, 21, 22
28	19, 20, 21, 22, 23
29	19, 20, 21, 22, 23
30	20, 21, 22, 23, 24
31	21, 22, 23, 24, 25
32	21, 22, 23, 24, 25, 26
33	22, 23, 24, 25, 26, 27
34	22, 23, 24, 25, 26, 27
35	23, 24, 25, 26, 27, 28
36	24, 25, 26, 27, 28, 29
37	25, 26, 27, 28, 29, 30
38	26, 27, 28, 29, 30, 31
39	26, 27, 28, 29, 30, 31
40	27, 28, 29, 30, 31, 32

Measuring the Shaft Length (Excluding the Glans)

Any length longer than a size 1 is 95% cosmetic.  There is no significant security benefit to the longer shaft.

Too short is better than too long.  Too long of a shaft cage will cause undue pressure on the glans and could cause irritation.  Too long of a measurement can also compromise security. The grip works similar to a finger cuff.  If the shaft is so long that it provides slight constant pressure against the glans, it is harder for the grip to be activated and create the clamping pressure needed.

Using the Length Guid included with the Sizing Rings

The sizing rings include a guide for measuring your length along the bottom of the shaft. Place the guide under your shaft. Looking down from above, choose the number that matches the point where your glans starts. The base end of the guide (starting at size 1) should be placed against the scrotum. The length guide should not be pushed into the scrotum; it should just lightly touch it. The shaft of the penis should lie on the guide itself. If you are between two numbers, pick the smaller of the two. Use the number to select your size when ordering your device. In the example below, the selected size would be 3.

Along the bottom

1. Ensure your penis is fully flaccid.
2. Place a ruler or measuring tape along the bottom of the shaft, starting where the shaft meets the scrotum.
3. Measure only the shaft length, stopping where the shaft meets the glans (do not include the glans itself).
   
4. Round this number to the nearest whole number.

 

Length Size

Size	Length Range
1	< 40mm
2	41-44mm
3	45-48mm
4	49-52mm
5	53-56mm
6	> 56mm

 

Measuring the Glans (Custom Only)

The glans measurement can be customized on the custom nylon product.  By default the glans length is 90% of the shaft diameter.  On the custom nylon product, this can be shortened or lengthened.  The short version will be 4mm shorter than standard and the long version is 4mm longer than standard. For the glans hood, longer is better than shorter for comfort.  Too short of a glans hood will cause the glans to always push backwards into the glans ring and will make the shaft more prone to hotspots.

This measurement is measured along the side of the glans along the center line of the shaft.  It should fall in the middle of the glans.  

 

For any questions regarding measurements or fit, please contact our support team at support@headzonedefense.com

Beta Guidelines

It's A BETA

Thank you for your interest in the HZD Beta Program. By participating in this program, you acknowledge and agree to the following terms:

1. Beta Product Disclaimer

The product you are purchasing is in its beta testing phase. It is an unproven, pre-release device that may have design, material, or functional imperfections. By participating in this beta program, you acknowledge that:

The product may not perform as expected and may require design modifications in future versions.

There is no guarantee of long-term durability, safety, or effectiveness.

The product is still undergoing testing and may be subject to updates or changes in later versions.

2. Assumption of Risk

By purchasing and using this beta product, you understand and accept full responsibility for any risks associated with its use. This includes, but is not limited to:

Discomfort, irritation, or other unforeseen physical effects.

Device malfunctions, failures, or breakages.

The potential inability to remove the device without external assistance.

HZD is not liable for any injury, damages, or consequences resulting from the use or misuse of the beta product. You are using this product entirely at your own risk.

3. No Returns, Refunds, or Warranty

All beta sales are final. Due to the experimental nature of this product, returns, exchanges, and refunds are not accepted.

There is no warranty on beta products. While we strive for high-quality manufacturing, the beta device is a test product and may require further refinement.

4. Feedback & Participation

As a beta tester, your feedback is crucial in improving the final product. By participating in the beta program, you agree to:

Provide honest and detailed feedback about your experience with the device.

Report any issues, discomfort, or malfunctions so we can improve future versions.

Understand that your feedback may be used to refine the design, materials, or function of the product.

5. Confidentiality 

Because the Grip chastity cage features a novel design, we require strict confidentiality regarding specific product details, particularly the glans grip ring mechanism.

By participating in this beta program, you agree not to disclose, share, or distribute the following information without explicit written permission from HZD:

Any detailed descriptions, sketches, photos, or videos of the glans grip ring and how it functions.

Any discussions about the internal mechanics of the device in online forums, social media, or private chats.

Any design specifications or modifications related to the grip mechanism.

Any attempts to replicate, modify, or reverse-engineer the design for personal or third-party use.

6. Program Termination

HZD reserves the right to modify or terminate the beta program at any time. Participants may also be removed from the program if they fail to comply with these terms.

7. Acknowledgment & Agreement

By purchasing and using the HZD Secure Beta Product, you acknowledge that:

You understand the experimental nature of the product.

You accept full responsibility for any risks associated with its use.

You waive any claims against HZD related to product performance, safety, or usability.

You agree to provide constructive feedback to help improve future designs.

If you have any questions about the HZD Beta Program, please contact us at support@headzonedefense.com

Thank you for helping us develop and refine a new, innovative chastity experience!

Terms of Services

Introduction

Welcome to HZD (“Company,” “we,” “our,” “us”). These Terms of Service (“Terms”) govern your use of our website [www.hzd.us] (“Website”) and the purchase and use of our products (“Services”). By accessing our Website or purchasing our products, you agree to comply with and be bound by these Terms. If you do not agree with these Terms, please do not use our Website or Services.

Eligibility

You must be at least 18 years old to use our Website and purchase our products. By accessing our Website or purchasing our products, you represent and warrant that you meet this age requirement.

Product Use

Our products are intended for personal use only. You agree to use our products in accordance with their intended purpose and any provided instructions. Misuse of our products can result in injury; we are not liable for any damages resulting from improper use.

Medical Disclaimer

HZD’s products are not medical devices and are not intended to diagnose, treat, cure, or prevent any medical condition. Consult with a healthcare professional before using our products, especially if you have any existing medical conditions.

Orders and Payment

Order Acceptance: All orders are subject to acceptance by HZD. We reserve the right to refuse or cancel any order for any reason.

Pricing: Prices for our products are subject to change without notice. The price charged will be the price in effect at the time of your order.

Payment: Payment must be made at the time of order placement. We accept various payment methods as indicated on our Website.

Shipping and Delivery

Shipping: We ship products to select locations. Shipping fees and delivery times are specified during the checkout process.

Delivery: Delivery dates are estimates and not guaranteed. We are not liable for delays caused by shipping carriers or unforeseen circumstances.

Returns, Refunds, and Cancellations

Due to the intimate and custom-made nature of our products, all sales are final. We do not accept returns or exchanges unless the product is defective upon arrival.

Defective Products: If you receive a defective product, please contact us within 10 days of receipt to request a replacement. We reserve the right to inspect the product before issuing a refund or replacement.

Custom Orders: Each item is made to order based on your specific selections. Because of this, orders cannot be canceled or changed once production has begun. Please double-check your measurements, color choices, and order details before submitting your purchase.

Intellectual Property

All content on our Website, including text, graphics, logos, and images, is the property of HZD and is protected by intellectual property laws. You may not use, reproduce, or distribute any content without our prior written permission.

 Privacy Policy

Your privacy is important to us. Please review our Privacy Policy to understand how we collect, use, and protect your personal information.

Limitation of Liability

To the fullest extent permitted by law, HZD shall not be liable for any indirect, incidental, special, or consequential damages arising from your use of our Website or products. Our total liability to you for any claim arising from these Terms or your use of our products shall not exceed the amount paid by you for the product in question.

Indemnification

You agree to indemnify and hold harmless HZD, its affiliates, and their respective officers, directors, employees, and agents from any claims, liabilities, damages, and expenses arising from your use of our Website or products or your violation of these Terms.

Governing Law

These Terms are governed by and construed in accordance with the laws of the State of Georgia, without regard to its conflict of law principles.

Changes to Terms

We reserve the right to modify these Terms at any time. Any changes will be effective immediately upon posting on our Website. Your continued use of our Website or products after changes are posted constitutes your acceptance of the revised Terms.

Contact Information

If you have any questions or concerns about these Terms, please contact us at:

HZD
1741 Newnan Crossing Blvd E
Ste I #2148
Newnan, GA 30265