Matser Series Urethral Sound Trainer Set is made of premium, phthalate free and non-porous silicone, these urethral sounds are easy to sterilize and body safe for an all new sounding experience. These flexible rods bend with the body, sliding down your shaft for that unique sensation that you crave. Each sound is double sided, with a different sized girth on each end. The graduated sizes allow you to work your way up until your stretched out piss hole can accommodate the largest rod! Measurements each sound is 8 inches in length. The smallest has a diameter of .19 inch on one side and .23 inch on the other. The medium is .27 inch and .32 inch in width. The large is .34 inch and .38 inch in width. Material Silicone. Color Blue.