Experience 2 ways to intensify your erection. Medical-style pump ball functions as an erection pump in one position and as a masturbation stroker in a second position – double the performance options of an ordinary pump. With each squeeze of the medical-style pump ball in the PUMP position a super-strong vacuum is created inside the chamber, forcing your erection to quickly expand its length and girth.MASTURBATION STROKER – When the pump ball is placed in the STROKER position your shaft is surrounded by super-tight oral sex suction. Twist the top dial to activate powerful multi-speed vibrations for additional stimulation.The soft TPR sleeve forms an air-tight seal against your skin, creating incredible suction and amazing results, while the crystal-clear tube is designed for a firm grip and has a convenient ruler to gauge your expansive growth. You can instantly relieve pressure by pressing the air release valve above the pump cylinder. Conveniently waterproof for fun in the bath or shower.Measures 13 in. long by 3 in. wide by 3 in. high. Insertable length is 6.5 in.