Designed around RKI sensors utilizing catalytic combustion, electrochemical, and galvanic sensing technologies, 2.95 x .98 x 2.75 in. GX-2009 simultaneously monitors and displays combustibles, oxygen, CO, and H2S. Dual audible alarm ports and alarm LEDs on 3 sides make alarm conditions obvious from multiple perspectives, even in high-noise environments. Other features include water-resistant and dustproof design with IP67 rating; datalogging system; and rechargeable NiMH battery set.