The silicone sounds are soft, flexible, and gentler than metal sounds so they are great for beginners and perfect for experienced users looking for a soft stretch. The graduated sizes make it easier for them to work their way up.-Mistress Isabella SinclaireMade 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!One of the most sought after Dominas in the world, Isabella Sinclaire has been a pillar of the fetish community and a fetish icon since 1993 and one of the first Pro Dommes with an online presence. She is a revered expert with an unparalleled knowledge on all types of BDSM activities and a deep understanding for those that participate in them. Isabella Sinclaire is also an international film star that has created or starred in over 60 BDSM films. The Isabella Sinclaire Signature Collection features exceptionally crafted tools of the trade, personally hand-picked by Isabella Sinclaire for your satisfaction. Each piece reflects her style, sophistication, skill and class.Measurements: Each sound is 8 inches in length. The smallest has a diameter of .19 inches on one side and .23 on the other. The medium is .27 inches and .32 inches in width. The large is .34 inches and .38 inches in width.