Designed to fit the body's inner contours the Vibro exerts pressure in all the right places while the five individual vibration settings are expertly primed. You can also choose from 6 vibration modes: low high slow pulse fast pulse and escalating. Waterproof. Uses a stainless steel roller ball massager to massage the perineum. Includes a 1.5 vote LR1 battery. Ribbed shaft measures 4 in. long 1.34 in. wide.