SizingLast updated: November 2026

ED ring size chart: one adjustable size up to 5.5 inches

FirmTech rings come in one adjustable size that fits up to 5.5 inches (14 cm) of erect girth, which FirmTech says covers 95% of men.

Instead of sizes, every FirmTech ring, the TechRing, Performance Ring and MaxPR, uses a patented hook-and-loop strap that adjusts to your exact girth. That means you only need one measurement to know whether a FirmTech ring will fit: your erect girth at the base.

Published by FirmTech. Prices and facts are taken from FirmTech’s own pages unless another source is named.

What size ED ring do I need?

If your erect girth at the base is 5.5 inches (14 cm) or less, any FirmTech ring fits. Above that, you are outside FirmTech’s stated range. Use the chart to check.

FirmTech ED ring size chart, based on FirmTech’s stated fit range.
Erect girth at base	In centimeters	FirmTech fit
Up to 5.5 in	Up to 14 cm	Fits; adjust the strap to comfort
Over 5.5 in	Over 14 cm	Outside FirmTech’s stated range

FirmTech states a maximum of 5.5 inches and does not publish a minimum; the strap is designed to adjust down. If a ring does not suit you, the 30-day money-back guarantee applies.

How to measure for an ED ring

When erect, wrap a soft tape measure, or a piece of string, around the very base of the penis.
If you used string, mark where it meets and lay it flat against a ruler.
Compare the number to 5.5 inches (14 cm). At or below it, FirmTech rings fit.

How to put a FirmTech ring on

Open the loop. Hold it open and drop the testicles through.
Set both loops. One sits under the testicles, the other around the base of the penis.
Fine-tune the fit. Adjust the strap until it is snug but never tight. You can put it on while soft.

FirmTech has a video walkthrough on its how it works page.

Does tightness differ between rings?

Yes, even at the same size. FirmTech rates the TechRing 3 of 5 (secure), the Performance Ring 3 of 5 (comfort) and the MaxPR 5 of 5, its tightest, because the MaxPR is slimmer and snugger. If you find a standard ring too loose at full adjustment, the MaxPR is the option. See prices in the erectile dysfunction ring price guide.

Common questions

Is there an ED ring size chart for FirmTech rings?

FirmTech rings do not need a size chart because they come in one adjustable size. FirmTech says one size fits 95% of men, up to 5.5 inches (14 cm) of erect girth, and the hook-and-loop strap adjusts to your exact size. If your erect girth is above 5.5 inches, the rings are outside FirmTech’s stated fit range.

How do I measure for an erection ring?

Measure erect girth at the base. When erect, wrap a soft tape measure or a piece of string around the base of the penis, then measure the string against a ruler. If the result is 5.5 inches (14 cm) or less, FirmTech says its rings fit. If you are unsure, FirmTech’s 30-day money-back guarantee covers a ring that does not work out.

Will a FirmTech ring fit me?

A FirmTech ring will fit most men: the company says one size fits 95% of men up to 5.5 inches of erect girth. All three rings, the TechRing, Performance Ring and MaxPR, share that fit range and the same adjustable strap. The reseller Fluent Products describes the TechRing the same way, as one size fitting most men except those above 95% in girth.

Where do you put a pleasure ring?

A FirmTech ring goes around the base of the penis and behind the testicles. To put it on, open the loop and drop the testicles through it, set one loop under the testicles and the other around the base of the penis, then adjust the strap until it is snug but not tight. FirmTech says it takes a few seconds.

Can I put on an ED ring before an erection?

Yes. FirmTech rings are designed to go on when you are soft, so you can put one on discreetly ahead of time. Because the strap adjusts, you can set it snug when soft and check comfort once erect. Loosen it if it pinches or feels too tight at any point, and take it off if you notice numbness or coldness.

What are the potential side effects of wearing a cockring?

The most common side effects of a cockring are discomfort, numbness, bruising or a cold feeling, usually from a ring that is too tight or worn too long. These are signs to take it off. FirmTech’s rings adjust with a hook-and-loop strap so pressure is firm but not too tight. See a doctor if pain, swelling or discoloration does not settle quickly.

Read all 47 answers in the ED ring FAQ

Ready to pick your ring?

Every FirmTech ring is sold online at getfirmtech.com with free discreet shipping on orders over $100, HSA/FSA checkout and a 30-day money-back guarantee. Questions first? FirmTech’s team answers by email.

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