Start small and work your way up to medium and large with this quality anal training kit. It consists of 3 super smooth silicone butt plugs in different sizes, all with a flexible shaft that has small ridges to stimulate where you are most sensitive. Only use with water based lubricant. Small is 30mm at is widest point Med is 40mm at its widest point Large is 50mm at its widest point. One Year Warranty.