How can you make penetration less deep? The Bumper is a firm silicone ring that can be worn on a penis or dildo that allows for penetration but controls the depth. Thicker in depth than a usual erection ring, the Bumper shortens penetration depth by 1 1/2″ allowing the person to feel penetration at full depth, while preventing the person being penetrated the pain of deep penetration. Except for the widest girth penises, the Bumper is unlikely to act to hold blood in an erection very effectively, but may help somewhat. Use a water based lubricant for easy on-off.