Power up for bigger, thicker erections with the Doc Johnson 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. Powerful Penis Pump. Push Button Control. Clear Vacuum Cylinder. Quick-release Air-valve Button. Soft Silicone Sleeve. Large Pressure Gauge. Made of Phthalate-free, Body-safe Material. Battery-operated; Requires 4 AA batteries. Total length: 12.70 inches. Usable length: 9 inches. Width/Diameter: 2.80 inches. Circumference: 8.80 inches.