Though the product can be used in air, the best results for gaining maximum enlargement and penile health is when it is used with water, either in the shower or the bathtub.
The strength of the Bathmate is it is designed by award winning engineers who fully understand the mechanics of vacuum when applied to the penis.
Traditional air pumps have been around for decades and virtually anyone with a workshop can apply a pump to a plastic tube and create a vacuum around the penis. That is not to say all air pumps are cheap and basic, some air pumps are quality products and are even used in hospitals to treat such as Erectile Dysfunction. It's Bathmate’s use of water to create the partial vacuum around the penis that makes it different and it is the understanding of pneumatics (air) as opposed to hydraulics (water) that has led to this revolutionary breakthrough in penis health and enhancement
So what is the difference between air and water in this context?
Air is spongy and compressible, which means if you create a vacuum inside a tube with air, the air that remains simply spreads thinner inside the tube. This means the penis can expand unevenly, creating possible bending and bulging of the penis.
This is why when using water as the vacuum media it is far more effective and powerful than air.
Article Source: http://hydromax-pump.com/