Oceanic VT 4.1 Scuba Diving Computer with Transmitter Powered by Oceanics Exclusive Dual Algorithm allowing you to choose the decompression algorithm that best suits your diving needs without compromising safety Deep Stop with Countdown Timer Switch between up to 4 independent wireless transmitters, tracking multiple Nitrox mixes 3-Axis Digital Compass with Full Tilt Compensation Improved user-interface with Step Back allows for easy settings preview and for settings to be changed while viewing the menus