Maintainance-Keep it clean avoid to be scratched. Use the disinfectant or alcohol cotton cloth to clean it can not be boiled or heated in water.This item not for medical. This high quality silicone cupping set is made from quality silicone. The silicone is soft and elastic which is easy to squeeze. Just squeeze the cups to an oval shape apply to the body and squeeze back to a circle shape for suction. Transparent cups also let you view the treatment area and reddening of the skin.