The cylinder should give you enough room to comfortably fit your penis and scrotum while flaccid. If you are filling up the cylinder, it is time to order the next size up. The cylinder should be tight enough to obtain a vacuum seal, while large enough to be comfortable.

Measure your penis using the instructions below to select a cylinder that fits properly and provides maximum expansion and comfort.

• Wrap a string around the ERECT shaft near the base.
• Mark where the ends of string meet.
• Lay string flat and measure the distance between the two marks with a ruler.