Auto diagnostics, menu driven state-of-the-art electronics, audible and visual HI-LO alarms, LO alarm 15-99% oxygen, HI alarm 16-100% oxygen, large backlit LCD for easy viewing, integral tripod stand and dove tail bracket. Proprietary advanced galvanic sensor capable of oxygen analysis from 0-100% and 60 months expected life in air. General purpose monitor operates 1,500 hours on 2 AA Alkaline batteries. Optional carrying case.