Imagine if a finger ring only came in three sizes equivalent to the circumference of a dime and a quarter and a dollar coin - how would they fit? Well until now, cock rings were sized even farther apart than this! No wonder finding a good fitting cock ring is near impossible. Perfect Fit has developed the first cock ring sizing system designed to fit you without too much pull but with enough restriction to be truly effective. We had to throw-away the sizing system that has become the de facto standard. We determined that we had to make rings that are only 0.1" (2.5mm) apart in sizing to get rings that would fit perfectly. The new rings are call Xact-Fit(TM). Now we make 14 Xact-Fit rings sizes where other manufacturers make only 3 to 5 sizes in this same range. We made them not too stretchy, so the rings are effective, but easier to get on and off than a metal ring. Our fun Play Zone kit contains the nine most used Xact-Fit sizes for shaft rings, ball rings, and cock & ball rings. We know you will be surprised at how this sizing makes all the difference. Made of a plush soft touch silicone the Xact-Fit ring is premium quality and incredibly strong. Each Xact-Fit ring is stamped with its size so no more guessing! Stack the rings for additional fun. If you if have favorite sizes you can order the perfect Xact-Fit size individually in the future. The Play Zone comes with a storage cone designed specifically to hold the Xact-Fit rings perfectly. The Play Zone comes with PF Size #11-#19. From Perfect Fit Brand.