Aqua Lung i300 Wrist, Black / Blue (Discontinued) 4 operating modes: Air, Nitrox, Gauge (with run timer), and Free Dive (tracks calculations to allow switching between DIVE and Free on the same day) User changeable battery and data retention. Maintains settings and calculations between battery changes Backlighting. For easy reading in low light Audible alarms and additional high-visibility LED warning light for additional safety User-updatable software gives access to the latest features and upgrade (must purchase optional download cable)