Mack Tuff Nipple Teasers Silver Black from Nasstoys of New York. Easy push button vibration. Pull straps to snug or loosen on nipples. Squeeze me till it hurts. Waterproof vibrations. Phthalates free, RoHS compliant materials Black is silicone, Chrome is ABS plastic. Size overall length 4.25 inches, width 1.5 inches, diameter .875 inch. Vibrating nipple clamps require 1 AAA battery each one, not included.