The Hydromax 8 penis pump from Bathmate is the world's most effective hydro vacuum erection device on the market. Fueled by water instead of air, the patented Hydromax pump provides consistent pressure around the penis, allowing for uniform expansion of the tissues. This revolutionary design increases the size and girth of the penis with long-term results. The Hydromax also improves penile blood flow, which creates more rigid erections, even when the pump is not in use. **The Hydromax 8 model is meant for current erect length 6"- 8.5" and girth up to 7" circumference (please keep in mind - every model has approximately 1.5" room for growth)** One Year Warranty.