Excellent performance in an ergonomic, rugged design. Heated diode sensor meets current SAE standards for sensitivity. Find leaks better than 0.1-oz./yr. Water-blocking filter adds a strong layer of protection for the advanced heated diode sensor. Visual/audible alarms trigger on CFCs, HFCs, HCFCs and blends. Automatic or manual calibration for testing in contaminated environments. Features: three sensitivity levels; non-conductive sensor arm; rechargeable, user-replaceable 15-hour lithium-ion battery; mute button; % battery charge check; and magnetic hanger.