Bathmate Hydromax 7 Aqua Blue Penis Pump for men 5 inches to 7 inches when erect. The water-based power of this pump is for users measuring between 5 inches and 7 inches when erect. Once filled with warm water, the pump seals against the body. For best results start with 3 five minute sessions per use. 1 to 3 months. Also available in clear and red. Internal length 10 inches.