The soft silicone sleeve forms an air-tight seal against the skin, creating incredible suction and amazing results, while the clear vacuum cylinder allows you to see your cock get bigger and fatter by the second! The tube is made from thick, heavy grade acrylic and marked with metric graduations to measure your growth. To prolong ejaculation, slide the included enhancement ring over your shaft until it's nice and snug. The tight squeeze will prolong ejaculation, help maintain your erection. and extend the fun.