Made of super-strong SKINFLEX-TPR. our best material for strength and serious stretch. Stretches 5X its size and snaps back every time.Dont worry about sizing. with 2 rings and the serious stretch these rings have. you will find your perfect fit.Skinflex-TPR. Phthalate FreeLube safe: water-basedCleaning: detergent and hot water. dishwasher. always wash and dry any stretchy sex toy after use. they will last longer.