Volume is an intuitive high-tech penis pump which allows the user to sit back while it does all the hard work - no pun intended - thanks to its incredible automatic mode. Right out of the box, Volume comes equipped with a USB chargers as well as a replacement waterproof ring for the controlled head. Slip inside from the silicone opening with comfort and enjoy Volumes two modes - automatic and manual. Simply put, Automatic mode allows the user to relax while Volume works its magic on its own. In Manual mode, the user can choose their desired pressure level. Want to see and track progress? Easily measure growth with the marked measurements along the side of the cylinder.