Mojo Bumpy Black from Electric Eel. Mojo’s Bumpy Double Penetration C-Ring. Five bumps on a sturdy silicone probe will be positioned perfectly for a smooth anal entrance once two stretchy silicone rings are in place around your, your partner, or your dildo’s shaft and balls. The rings are nice and snug without being uncomfortable they are more for probe support than erection support, though they will help with that, too. Material: Silicone Dimensions: overall length 6 inches, insertable inches 5.5 inches Bumps, rings range from 1.5 inches to 2 inches in diameter.