Power up for bigger, thicker erections with the OptiMale Power Pump. Watch your growth through the large, clear vacuum cylinder, featuring a soft silicone sleeve for an air tight seal, a stylish pressure gauge, and an easy to read measuring guide to monitor progress. The strong auto pump action is easily delivered with just the push of a button, and a quick release valve button allows for customizable pressure. The Power Pump helps draw blood flow to your penis for the ultimate erection, increasing your size and sexual satisfaction. Made of phthalate free, body safe materials. Penis pump requires 4 AA batteries, not included.