Robinair's Infrared Refrigerant Leak Detector, No. 22791, fits naturally in the user's hand and its ruggedized construction stands up to abuse that most other leak detectors cannot handle. It automatically recalibrates in highly contaminated areas to help pinpoint the exact location of a leak and it won't trigger on oil or moisture. Eight-hour battery life lets you work all day before recharging and the advanced infrared sensor is designed to last a minimum of 10 years.