Single-gas detection for carbon monoxide, hydrogen sulfide or oxygen that will operate for over 2 years. Offers superior dust/water protection and high resistance to RFI. Rubberized housing and 1-button operation provide durability and ease to use. Features triple alarm system with (2) bright LEDs and audible/vibrating alarms. Automatically records last 25 alarm events. MSA infrared adapter with build-in IR communication port enables user to read data or change alarm set points Small, thin sensor profile provides high performance in very small package.