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Sizing Rings

(9 customer reviews)


ESSENTIAL! Our 3D printed Sizing Rings take the guess work out of finding your perfect fit and each set comes with a $50 or $60 Discount Code to spend on a metal ring when you are ready.

King Rings’ 2mm size granularity makes a tailor fit experience possible, our sizing rings are the best way to take advantage of this. Whether you are new to penis rings, an experienced user, or a long time collector, our Sizing Rings are a valuable tool. Not only are they “less than free”, these rings can help you spend your money smarter.

Free shipping in the US. | Discounted International Shipping

Read more below for important details!

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Be assured of a perfect fit! Our 3D printed Sizing Rings are the same dimensions as our heavy metal rings and will help you discover your perfect fit prior to investing in a lifetime accessory. We print them with body safe, biodegradable PLA plastic and color shades vary. Our size range is adequate for about 95% of men but it is recommended you verify you are in range with our Sizing Guide.

Included in the Full Kit:
– Cock Ring Set; 8 sizes. 44-58mm
– Glans Ring Set; 5 sizes, 24-32mm
– Finger Ring Sizing Tool
– Printed Sizing Guide and other information
– Small piece of sandpaper, just in case

Sizing Guide: Included with every kit, this printed brochure contains more helpful information than you will find on this site. Its contents are proprietary and developed over years of coaching gentlemen through the fitting process.

Less Than FREE – Each set of rings comes with a Discount Code worth $50 or $60! The code is valid for 6 months, can be used to buy any regularly priced metal ring, and cannot be combined with other offers or discount codes.

Free Shipping: No cost USPS First Class shipping to U.S. addresses. International shipping is discounted, see prices during checkout.

Do It Yourself: Download the 3D models and print the rings yourself or with the help of a local print shop. If you live outside the U.S. this could be a good option, ask us about our DIY discount when you come back for a metal ring in your preferred size.

Get A Single Ring at Checkout: You also have the option to add a single Sizing Ring to any metal ring order during checkout. This will allow you to verify your ordered size before unsealing the high value ring (see our Returns Policy) but what you don’t get is the opportunity to compare different sizes.

Photo Disclaimer: Many of the product graphics on this page are not photographs but are computer generated from 3D models. Actual rings are shown below.

Cock and Glans Sizing Rings

Product Data


PLA plastic, Biodegradable


Cock, Glans, Cock & Glans, Cock & Finger, Glans & Finger, Full Set

Band Width

Glans: 15mm, Cock: 20mm

Band Thickness



Colored by size as shown, shades vary

Reference Info

Sizing Guide | Fitting Guide | How To Wear | Care and Cleaning

9 reviews for Sizing Rings

  1. daretoask88 (verified owner)

    The sizing rings work great, I went for the full set and even though it turns out a glans ring was no option for me, it did give me the option with this measuring set to check for a nice “shaft” ring instead!

    I stole Konrad F’s idea and will use this set when I go swimming so I do not have to worry about damaging the brand new c-ring

    • Scott King

      We are glad you had success with your sizing rings and were also enabled to experiment with an unexpected use. The sizing rings are water proof, float very well, and can be a fun toy in the pool, sea, or lake. We recommend rinsing them with fresh water after and drying before storage – same as our metal rings. On that note, only our gold plated rings are vulnerable to tarnish in chlorinated or marine water (same as all gold). You can confidently wear all of our other rings while swimming or soaking.

  2. Scott M (verified owner)

    These sizing rings were fantastic in allowing me to dial in my Goldilocks fit. I wanted to find the size that would allow me to wear a ring all day but still get good constriction when hard. The added discount code made this a no brainer purchase!

  3. Dustin G (verified owner)

    These are a great value and they’re good for first time users of cock/ glan rings compared to the cheap rubber band ones. That don’t really work for a daily driver type of rings.
    Now I’m wondering if the metal ones grip my member better than these?

    • Scott King

      Our plastic sizing rings are perfect for assessing the physical fit of our metal rings and exploring the comfort of a wide band. However, they are a poor proxy for the experience of wearing a heavy Tungsten Carbide ring all day. Our printed Sizing Guide (included with your Sizing Rings) suggests you should identify which ring size is too small and then purchase one size larger. This is the best way to determine which size is most appropriate for use in both contexts; casual and playtime.

  4. Jason (verified owner)

    I have never worn a ring before so very glad I decided to start with the sizing rings. They are amazing for getting used to the thickness and the feeling of wearing a ring. The only thing I personally would suggest is that once you find one that is comfortable, see if you can fit in the smaller size and still be comfy hard as when I gave them to a friend to try he chose a size and wished he had gone one smaller when he purchased an actual king ring because the weight made a big difference. Being small when soft I thought the 52 was best but once he told me that I tried the 50 and was still able to have an amazing release so ordered a 50 and have to agree with the weight it stays in place better being a size smaller.

  5. Kevin (verified owner)

    These were very helpful to me in the decision making process of which C-ring to buy. I have worn cheap metal and stretchy c-rings before. The metal rings were all too small and painfully tight. The stretchy ones pinched and were too elastic to constrict blood flow during sex. I would recommend anyone considering purchasing one of King Ring’s metal rings purchase a set of sizing rings, even if you’ve worn C-rings before and think you know your size. For one thing, these are less than free with the generous coupon which you will receive. Secondly, I found that the experience of wearing a 20mm wide ring vastly different from the narrow, cheap, metal rings. In my experience, the extra width added to the comfort of wearing the ring for extended periods and improved constriction when erect.

    I ordered a 50-58mm set of sizing rings and Scott was kind enough to throw in a 64mm ring as well. Dealing with Scott was an absolute pleasure. He answered my questions amazingly quickly and was very helpful. He really wants you to be happy with the “real” ring you eventually purchase and confident that it will be the correct size.

    Wearing these sizing rings will make you even more eager to get one of King Ring’s gorgeous creations.

  6. Michael H (verified owner)

    These were perfect for learning how to put on a ring. I was so glad I ordered a set. It got me acclimated to wearing a ring with such an awesome thickness – after a few days of all day wear, I almost forgot I had one on during the work day. I also now know that there are three sizes I can comfortably wear, and which of these three is my ideal Goldilocks fit. Customer service was great, and Scott checked in a few days after delivery to see how the fit was and to let me know he was available for any questions about sizing and fit. And it promptly came with a coupon for my final King Ring order!

  7. Augustine (verified owner)

    I’m so glad that King Rings offer the sizing rings. Me and my husband have both worn cock rings but nothing with this thickness before. It’s awesome! we both found our size and wearing the daily and trying on the different sizes to find out perfect match. We’re both still deciding on what ring we want to purchase as our “daily driver.” Hoping to pick up two soon! Thank you Scott!

  8. Danny (verified owner)

    A unique offering and excellent first step towards choosing a King Ring. Great for practicing how to put on and take off a ring, especially for the newbies. Also helpful in understanding how a ring of this thickness will feel worn for long periods of time under clothing, with or without underwear, and also during arousal and release. A smart purchase before deciding on a metal ring.

  9. Konrad F (verified owner)

    I bought these to make sure I was getting the correct size. They are light weight and comfortable to use. After finding my size I think I could even use these while swimming in a chlorinated pool so I won’t have to worry about damaging my good one. Included is some fine sandpaper to smooth out any rough edges – thoughtful touch.

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