Three alarms functions - audible, visual, and vibration - make alarm conditions clear The monitor features a robust, rubber-coated weatherproof polymer housing rated to IP65 that will stand up to the typical abuse in an industrial environment. Easily operated using just two buttons. Its small size makes it comfortable and easy to wear all day on a belt, pocket, or lapel. A loud audible alarm, two bright visual alarms, and strong vibrating alarm alert you to hazardous concentrations of gas. Built-in event logger stores up to 60 alarm activations or other events. The Pac 3500 is a maintenance-free detector with a two-year sensor life. Approval: UL and cUL classified intrinsically safe in Class I, Div. 1, Groups A, B, C, D, E, F, G T4; ATEX; CE What's included: Pocket/belt clip and batteries