Prostate massager let's you regulate the 10-speed vibration area as well as the 2 electro shock areas, for extra stimulation. E-stim devices deliver a variety of impulses, from a gentle tickle to a heavy throbbing throughout the body. Waterproof during vibration, not e-stim. The electroshock function will only be activated when the ribbed parts touch the skin simultaneously. Measures 4.7 in. long, 3.54 in. insertable, 1.54 in. diameter.