This is the Cressi Sub Giotto Mixed Gas Scuba Diving Computer Air, Nitrox and Gauge Modes Features: Software handles two different hyper-oxygenated mixtures Tissues: 9 saturation half-times ranging from 2.5 to 480 minutes Dive" Program: Full processing of dive data, including decompression if applicable, for every dive performed with Air or Nitrox Full setting of FO2 parameters (oxygen percentage) and PO2 (oxygen partial pressure) with the option to set PO2 between 1.2 bar and 1.6 bar, and FO2 from 21% and 99% Option to take a Nitrox dive after one with air (even while desaturating) Gauge setting option (depth gauge and timer) Deep stop can be turned on or off Replaceable protective display screen User-replaceable batteries Planning: decompression curve scrolling User can switch units of measure from Metric (meters and C°) to Imperial (feet and F°) Visual and auditory alarms Graphic CNS oxygen toxicity indicator Backlit display Built-in calendar and clock Log book (70 hr or 60 dives) complete with dive profile Dive history saved Option for full reset if needed, helpful when renting the device Giotto is the first Mixed Gas dive computer designed and built entirely by Cressi The 3 button interface makes it effortless to program Air, Nitrox and Gauge modes from the first time a diver picks the computer up. The high-definition screen gives large numerical displays in a computer that is still compact and travel-friendly. The clearly visible battery life indicator and distinct audible alarms deliver critical information as well as peace-of-mind during the dive. The Giotto can also be fully re-set after each use, making it an excellent choice for rental departments. It has a new algorithm created through a collaboration between Cressi and Bruce Wienke based on the Haldane model, integrated with RGBM factors for safe decompression calculations in repetitive multi-day dives and with mixtures. "