A precision blend of sophisticated computer and beautiful timepiece, the MANTIS 1 (M1) is very similar to SCUBAPRO's new M2 in form and function. The M1 is the wristwatch-style dive computer for divers who want the Smart technology offered by SCUBAPRO's ground-breaking Human Factor Diving but who don't need air integration or an on-board digital compass. Technical Information Targeted to recreational and technical divers as well as CCR divers and freedivers. Predictive Multi-Gas ZHL8 ADT MB algorithm accommodates three gases (21-100% O2). PDIS (Profile Dependent Intermediate Stops) calculates an intermediate stop based on N2 loading, current and previous dives and breathing mixes for safer diving. Microbubble levels let you adjust the level of conservatism in the algorithm to match your experience level, age and physical conditioning. Optional heart rate monitor records heartbeat and skin temperature (with SCUBAPRO HRM Belt only) that can be factored into the decompression calculation along with workload. Casing is built from the highest marine grade 316L stainless steel with a two-toned brushed finish that both protects and looks great. Magnetic control buttons eliminate the need for holes, maintaining the casing's watertight integrity and maximizing mechanical reliability. Great for freediving. PLUS: Four Dive modes: Scuba, Gauge, Freediving and CCR. Swim mode. Full topside time-keeping functions. Chronograph with lap memory for running. Fixed PPO2 CCR algorithm. Maximum operating depth: 394ft/120m. Segmented LCD display. Protective mineral glass. Easy-to-read characters and graphics. Enhanced logbook for freediving. CR2032 dealer replaceable battery rated for two years/300 dives. PC and Mac compatible using LogTRAK with optional cradle.