The IQ-900 Zen is TUSA's latest full-featured wrist-top, watch style computer. The Zen is a stylish instrument that can be worn at the office, on the town or in the ocean - anytime, anywhere the Zen is your go to timepiece and dive instrument. The IQ-900 can be operated as a watch, Air computer, Nitrox (EANx) computer, digital depth gauge/timer or as a free dive depth gauge/timer. The Zen's large alphanumeric and backlit display allows for high legibility in or out of the water, although its size is that of a normal style watch. In addition to offering the latest comprehensive computer features, the Zen adds a Deep Stop function for enhanced safety. Features: * Advanced 2 gas wrist-top (watch) computer. * Air, Nitrox, Gauge, Free Dive and Watch Operating Modes. * 2 Mix Switching Feature: Mix 1 (Air, 21-50%), Mix 2 (Air, 21-100%). * Manual or Water-Activation. * Audible and Flashing Icon Alarms. * Large alphanumeric and backlit display. * Advanced user safety settings. * Deep Stop Feature and Safety Stop. * 1 Touch Log Access. * Automatic altitude adjustment from sea level to 14,000'. * No fly icon, residual nitrogen discharge time display. * PC download and upload settings/log data with TUSA Datalog Interface. * User-replaceable battery with hot-swap (Battery: CR2430, 3V). * TUSA Algorithm based on Buhlmann ZHL-16c. * Variable Ascent Rate Indicator. * Colours: Titanium Grey/Black, Black. Deep Stop Function Several TUSA computers feature an optional deep stop function for additional safety. The deep stop mode is activated when a dive exceeds 80 FT (24M) for more than 1 second. Upon ascent, the computer will display a Deep Safety Stop screen and the recommended stop depth for a period of 2 minutes. This deep stop is highly recommended as additional opportunity to off-gas, but is not mandatory. If the diver chooses not to serve the stop it will not adversely affect the remaining No-Decompression Limits of the dive. * Activated when depth becomes greater than 80 FT (24 M) for more than 1 second. * Deep Stop screen appears upon ascent(s). * Recommended Stop Depth is displayed and Stop Time as min:sec, counting down from 02:00 to 0:00. * Deep Stop feature is disabled upon entry into Decompression Mode. * The Deep Stop feature is recommended for additional safety, but is not mandatory.