Entry level computer featuring Air,Nitrox and Gauge Modes Three levels of conservation that the user can adjust Speed ascent control 10m per minute Modified Haldane and Wienke dive tables are used to calculate saturation The Log book can hold up to 60 dives or 75 hours worth of dive information and it is updated every 20 seconds Compact unit with a large ,Hi Definition screen Easy to read numbers Battery indicator on the display Beeps are very audible under water One front button controls all functions of the computer A quick press of the button changes the function of the computer and a long press selects the function No wet contacts are used on the unit which insures that rust will not be a factor User replaceable battery- USED HAS 26 DIVES ON LOG