XO 4-2 offers a broad range of advanced possibilities, not found in XO 4-1. XO 4-2 is equipped with a display, and allows precise and hands-free control of the unit instruments, using the XO Foot Control. Other advantages include: Built-in main water/air valves and leakage sensor Two extra buttons on the foot control for accessing additional functionality A small display on the instrument bridge More precise control of micro motor (100-40.000 RPM) Hands-free control of speed levels and spray water levels Access to other accessories not available for XO 4-1 User interface The user interface of XO 4-2 consists of an XO Foot Control, with two additional buttons, and a display on the instrument bridge. The extra buttons on the foot control are used to access additional functionality, not available on XO 4-1. The display consists of 8 alphanumeric digits (red), showing the primary instrument parameter, 3 green LED's showing the amount of spray water, 1 blue LED indicating the presense, or absense, of spray air and 1 white LED indicating the status of XO Instant View (enabled/disabled).