Integral to Compass is the INFICON patented heated diode sensor technology, delivering outstanding sensitivity to all refrigerants yet resisting jobsite contaminants such as dust, dirt and oil. For maximum versatility and ease of use, Compass has features such as rechargeable batteries, the ability to operate on AC power, adjustable high/low sensitivity and a series of LED leak indicators. The ergonomic design with rubberized grip fits your hand perfectly for comfortable, secure operation.