Compact, rugged in design and fully serviceable with simple 1-button operation. Visual alarms are high-visibility yellow and red, housed in a 3-light window. Audible alarms are 10% louder than previous model. Max, STEL and TWA readings are accessible by pressing the MODE button. Continuous real-time gas readings at all times; even during alarm. Black Box® recorder and event logger are standard. Meets IP65/IP67 water ingress protection. Compatible with the IQ Express docking station. Meets c-UL-us. Classified for Class I, Div. 1, Groups A, B, C, and D T4. UL® classified for Class II, Div 1, Groups E, F, and G.