The Extech RD200 Refrigerant Leak Detector is ideal for detecting leaks from air-conditioning units and cooling systems that use all standard refrigerants. The multi-colored LED light bar indicates the level of refrigerant detected by the RD200. Features a field replaceable heated diode sensor and Low/High sensitivity range selection for accurate leak detection. The 16 in. (406mm) flexible gooseneck provides easy access in difficult to reach locations.