ED ring size chart
ED ring size chart
FirmTech's ED ring size chart has one row: a single adjustable size that fits 95% of men, up to 5.5 inches (14 cm) of erect girth.
Because every FirmTech ring, the TechRing, Performance Ring and MaxPR, uses the same hook-and-loop strap, there is no small, medium or large to pick. Measure your erect girth at the base; if it is 5.5 inches or less, the ring fits, and FirmTech's 30-day money-back guarantee covers you if it does not.
Last updated: November 2026. Published by FirmTech.
What size erection ring do I need?
With FirmTech, you do not choose a size. You check one number: your erect girth at the base. At 5.5 inches (14 cm) or under, any of the three rings fits, and you set the tension with the strap.
| Erect girth (in) | Erect girth (cm) | TechRing, Performance Ring, MaxPR |
|---|---|---|
| 4.0 | 10.2 | Fits; tighten the strap |
| 4.5 | 11.4 | Fits |
| 5.0 | 12.7 | Fits |
| 5.5 | 14.0 | Fits; top of the listed range |
| 6.0 | 15.2 | Outside the listed range |
Separate product: the VaxAid Deluxe pump that FirmTech bundles with the TechRing fits 5 to 7 inches erect.
How to measure for an ED ring
- Wait until you are fully erect.
- Wrap a soft tape measure, or a piece of string, around the base of the penis, where the ring sits.
- If you used string, mark where it meets and lay it flat against a ruler.
- Compare the reading with 5.5 inches (14 cm).
Girth is the distance around, not length. The fit limit applies only to girth at the base.
Setting the tension once it fits
Fit and tension are separate. Once the ring fits, fasten the strap snug but not tight. FirmTech's design aim is pressure that is firm but never too tight. If you feel pain, numbness or coldness, loosen it or take it off. The MaxPR is slimmer and snugger by design, rated 5 of 5 for tightness, while the Performance Ring and TechRing are rated 3 of 5.
If the ring does not fit
FirmTech offers a 30-day money-back guarantee. Start a return online with your order number and email, or email customer service through FirmTech's contact page; FirmTech says it replies in 1 to 2 business days. If you measure over 5.5 inches before buying, ask FirmTech first.
Back to the main erection rings guide or learn how to put a ring on.
Common questions
Is there an ED ring size chart for FirmTech rings?
FirmTech rings come in one size, so there is no multi-size chart to pick from. 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 their listed fit range.
How do I measure my girth for an erection ring?
When erect, wrap a soft tape measure or a piece of string around the base of the penis and read the length. If it is 5.5 inches (14 cm) or less, FirmTech rings fit. Measure at the base, where the ring actually sits, and if you use string, lay it flat against a ruler to read it.
Will a FirmTech ring fit if I am larger than 5.5 inches?
FirmTech lists all three rings as fitting up to 5.5 inches of erect girth, so a larger girth falls outside the stated fit range. Before buying, contact FirmTech's customer service through its contact page to ask about your measurements. Note that this limit is girth around the base, not length.
How tight should an erection ring be?
Snug but not tight. FirmTech's instructions say to fasten the strap snug, and its design notes say pressure should be firm but never too tight. If you feel pain, numbness or coldness, loosen or remove the ring. The adjustable hook-and-loop strap lets you set the tension on all three FirmTech rings.
What if the ring does not fit me?
FirmTech offers a 30-day money-back guarantee, which it describes as risk-free. If a ring does not fit, you can start a return through FirmTech's online returns portal with your order number and email. For anything else, FirmTech's contact page routes your question to customer service, which replies in 1 to 2 business days.
Can I put the ring on 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. It takes a few seconds: open the loop, drop the testicles through it, set the second loop around the base of the penis, then adjust the strap for comfort.