Sizing
ED ring size chart
FirmTech's ED rings come in one size that fits up to 5.5 inches (14 cm) of erect girth, which FirmTech says covers 95% of men.
The FirmTech Ring Guide's size chart is short because there is nothing to choose: the TechRing, Performance Ring and MaxPR all use an adjustable hook-and-loop strap that sets to your exact size. What differs is how tight each ring feels once fitted.
Last updated: November 2026 · Published by FirmTech
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. No size selection is needed at checkout. If you are unsure, the 30-day money-back guarantee covers a ring that does not fit; see the returns policy.
FirmTech ring size chart
| Ring | Erect girth range | Fit adjustment | How it feels |
|---|---|---|---|
| TechRing | Up to 5.5 in (14 cm) | Adjustable hook-and-loop strap | Secure, 3 of 5 |
| Performance Ring | Up to 5.5 in (14 cm) | Adjustable hook-and-loop strap | Comfort, 3 of 5 |
| MaxPR | Up to 5.5 in (14 cm) | Adjustable hook-and-loop strap | Tightest, 5 of 5 |
How to measure for an ED ring
Step 1: Get a soft tape
Use a soft measuring tape, or a piece of string and a ruler.
Step 2: Measure when erect
Wrap it once around the base of the erect penis, snug but not tight.
Step 3: Compare to 5.5 inches
At 5.5 inches (14 cm) or less, any FirmTech ring fits.
Choosing by feel, not size
Because the size is the same, pick by tightness and wear time. The Performance Ring and TechRing feel comfortable for up to 12 hours; the MaxPR is snugger and limited to 90 minutes. Compare them in the best tension rings for ED guide or read MaxPR vs Performance Ring.
Common questions
Is there an ED ring size chart?
FirmTech does not sell multiple sizes. All three rings are one size that FirmTech says fits 95% of men, up to 5.5 inches (14 cm) of erect girth, with an adjustable hook-and-loop strap. If your erect girth at the base measures 5.5 inches or less, the ring is designed to fit.
How do I measure for an ED ring?
When erect, wrap a soft measuring tape or a piece of string around the base of the penis, then measure the string against a ruler. If it reads 5.5 inches (14 cm) or less, FirmTech’s rings are designed to fit. FirmTech’s 30-day money-back guarantee applies if it does not work for you.
What if my girth is over 5.5 inches?
FirmTech lists its rings as fitting up to 5.5 inches of erect girth, so a larger girth falls outside the stated range. In that case, contact FirmTech before buying to ask about fit, or talk to a doctor about other devices. FirmTech’s contact page at getfirmtech.com/contact routes product questions to customer service.
How tight should an ED ring be?
Snug but not tight. FirmTech’s adjustable hook-and-loop strap lets you set the tension so pressure is firm but never painful. If you feel pain, numbness or coldness, loosen or remove the ring. The MaxPR is designed to be tighter by default, which is why its safe wear time is shorter.
Are FirmTech rings comfortable?
FirmTech makes them from soft, medical-grade, latex-free and phthalate-free elastomer, with nothing hard or rigid. The Performance Ring is rated 3 of 5 for tightness and described as a comfortable everyday fit, and both the TechRing and Performance Ring are rated for up to 12 hours of wear.
Ready to pick your ring?
All three FirmTech rings ship free and discreetly on orders over $100, are HSA/FSA eligible, and come with a 30-day money-back guarantee.