Now you can see the status of your gas system at a glance, even in dim light. Universal symbols on the back-lit display and membrane switches show you everything you need to know, eliminating the need to read the small print found on most electronics panels. This makes operation truly intuitive. This gas detector monitors up to two remote sensors, allowing the detection of leaks in different locations at the same time. If there is a leak, and the concentration reaches 15% to 25% of the lower explosive level, the display flashes a warning and the audio horn pulses and alarm. As soon as residual fumes drop to a safe level, the detector diplays the "OK" symbol. This unit is simple to install, comes with one remote sensor head and cable, and is backed by a hassle-free 2 year parts & labour guarantee. DIMENSIONS: 3.75"H x 5.20"W x 1.25"D (flush depth 0.375"), Power Required: 12VDC 200mA, Sensitivity: 15-25%, Alarm Output: 85dB SURFACE MODEL SHOWN.