The O2 Quickstick is designed specifically for Nitrox Diver. A simple twist of the side knob will open and calibrate the analyzer to ambient air. Place the O2 Quickstick over the slightly open tank valve to ensure an accurate and reliable reading. The intuitive process requires only one hand to operate. Replaceable thermally compensated sensors maintain accuracy that exceeds diving industry standards. The analyzer can be conveniently turned off after use to preserve battery life and stored in your dive bag. The anodized Marine Grade aluminum body used in submersibles can withstand dive tanks and weight straps in a rugged environment. The O2 Quickstick comes with a 1-year limited manufacturer's warranty and the sensor is supplied with a 2-year prorated warranty.