Slipping on and cinching up nice and easy, each Stimulator features an adjustable design able to capture even the smallest sections of nerve-ending rich nipple. A silky silicone loop can be tightened and loosened by sliding a jet black bead up or down. Once in place, push the underside of each embedded vibe to activate a single speed of reliable vibration targeted straight to the nipple(s). Easily cleaned, Frederick's of Hollywood Vibrating Nipple Stimulators come to you in high end premium silicone. Wash well using warm soapy water or a good toy care fluid/foam before and after use. Each vibe requires 3 LR44 cell batteries, which are included. Not rated for use in water.