The Hydromax-series is the next stage of Hydro Pump evolution. Developing the innovative Bathmate, the new bellows pump and valve give 35% more power for even greater gains with more safety and comfort. By introducing new materials into the mix we have been able to create a unique bellows system that is not only stronger and more durable but also gives more flexibility, allowing you to create greater suction with less effort.The internal bellows size has also been increased and the number of convolutes reduced giving you plenty of room for increased girth expansion. If you measure around 5 inches or less when erect, you’ve found an ideal hydropump option. With a powerful water-based design, Hydromax5 generates real, lasting results.