With a total cylinder length of 20 cm (7.8) and a inner diameter of 6 cm (2.36), this high-quality pump gives you ample possibilities to grow in both directions! The insertion sleeve is made of smooth Silicone. Surprise yourself every time on how big you can get! At the touch of a button the extremely powerful pump will create a super-strong vacuum, giving you a quick and powerful erection. The soft silicone opening will create a tight yet comfortable seal. Takes 2 AA batteries (not included). WARNING: Please read product manual before using any type of vacuum pump orconstriction ring. Stop using the devices immediately if you experience any pain or discomfort.