Fits all nipple sizes. Hands free nipple teasing. Powerful vibration. Squeeze bulb, place over nipple, then release. Waterproof vibrating nipple suckers. Phthalates free, RoHS compliant materials Silicone bulb with ABS plastic vibrating bullet. Size overall length 2 inches, width 2 inches, height 3 inches. 4 LR754 batteries included 2 in each nipple sucker. 4 extra batteries also included.