You will need a way to measure: a cloth tape, or a shoelace, string, etc.
Measurements should be made while erect.
The Pinnacle and The Clarifier
These are not round, so the string-to-diameter method below will get the wrong shape. Use the fitting tool on the product page instead — it is easier.
Measure two numbers, in millimetres, while erect:
- Width — side to side
- Depth — front to back
Enter those on the page and let it pick the shape. You can also send the two numbers in Discord or by email.
The Pinnacle — tip / under the corona
The Clarifier — bipolar shaft ring
Round rings (The One, Underball, Fat Ring, Propper)
IMPORTANT: These rings are sized by diameter, but you will be measuring circumference with string.
To convert: Circumference ÷ 3.14 = Diameter (ring size). A full conversion list is at the bottom of this guide.
The One (shaft ring) — wrap the string ONLY around the base of the shaft, right up against your body. The string does NOT go under the balls. Pull it snug but not tight. This is the one that changes size the most from flaccid to erect. I use one 1–3mm smaller than my measured size so it contacts well when starting flaccid and acts as a cock ring when erect.
Since rings are circular but the penis is not perfectly round, they fit slightly tighter than the string suggests. Usually 33–43mm diameter (104–135mm circumference).
The One Underball — wrap the string around the very base of the penis AND under the balls (the whole package). Pull it snug but comfortable. Easier to size; flaccid-to-erect does not change this one as much. Measure erect, put it on flaccid. Usually 45–55mm diameter (141–173mm circumference).
Circumference to Diameter Conversion
- 94mm (3.70") → 30mm diameter
- 97mm (3.82") → 31mm diameter
- 101mm (3.98") → 32mm diameter
- 104mm (4.09") → 33mm diameter
- 107mm (4.21") → 34mm diameter
- 110mm (4.33") → 35mm diameter
- 113mm (4.45") → 36mm diameter
- 116mm (4.57") → 37mm diameter
- 119mm (4.69") → 38mm diameter
- 123mm (4.84") → 39mm diameter
- 126mm (4.96") → 40mm diameter
- 129mm (5.08") → 41mm diameter
- 132mm (5.20") → 42mm diameter
- 135mm (5.31") → 43mm diameter
- 138mm (5.43") → 44mm diameter
- 141mm (5.55") → 45mm diameter
- 145mm (5.71") → 46mm diameter
- 148mm (5.83") → 47mm diameter
- 151mm (5.94") → 48mm diameter
- 154mm (6.06") → 49mm diameter
- 157mm (6.18") → 50mm diameter
- 160mm (6.30") → 51mm diameter
- 163mm (6.42") → 52mm diameter
- 166mm (6.54") → 53mm diameter
- 170mm (6.69") → 54mm diameter
- 173mm (6.81") → 55mm diameter
- 176mm (6.93") → 56mm diameter
- 179mm (7.05") → 57mm diameter
- 182mm (7.17") → 58mm diameter
- 185mm (7.28") → 59mm diameter
- 188mm (7.40") → 60mm diameter
- 192mm (7.56") → 61mm diameter
- 195mm (7.68") → 62mm diameter
- 198mm (7.80") → 63mm diameter
- 201mm (7.91") → 64mm diameter
- 204mm (8.03") → 65mm diameter