Due to the consistent nature of hydraulic pressure created by the Bathmate range of pumps, the users penis will increase in girth a lot quicker than it will in length. This is because the surface area is greater around the girth of the penis than the length. This will result in the penis touching the sides of the pump, meaning the hydraulic pressure will not be able to expand the girth of the penis further. The Wide Boy has a wider vessel but no increase in length on the X30 meaning that optimum hydraulic pressure is maintained, resulting in quicker growth.