Cressi Leonardo A single button Dive Computer makes effortless to set Air, Nitrox and Gauge modes. Ideal for beginners in Scuba Diving. It is easy to use, easy to read all the information due to the high-definition screen that gives large numerical displays. FO2 adjustable between 21% and 50%. PO2 adjustable between 1.2 bar and 1.6 bar. CNS oxygen toxicity graphic indicator. Three levels of user adjustable conservatism. Visual and distinct, easy-to-hear audible alarms. User-selectable deep stop function. Adjustable unit of measure: imperial or metric. Battery life indicator. User changeable battery. Battery model: CR2430. The interface (not included) uses IR to connect to the diving computer and a USB cable for PC connection. Software compatible with all versions of Windows and with Mac. The Leonardo dive computer is made in Italy by Cressi, a brand pioneer in Scuba Diving, Snorkeling and Freediving equipment.