Weighing only 4.6 ounces, it fits in the palm of your hand (2.75? H x 2.95? L x .98? D). The GX-2009 monitors and displays combustibles, oxygen, carbon monoxide, and hydrogen sulphide. With dual audible alarm ports and alarm LED?s on 3 sides of the instrument, so that alarms are obvious from multiple perspectives like high noise environments. Other features include a waterproof and dust-proof with IP 67 rating, an impact resistant rubber over-mold body, and a large capacity data logging system.