Electronic Refrigerant Leak DetectorElectronic Refrigerant Leak Detector Optimum sensitivity detects leaks down to 0. 25 oz year (7 g year) Sensor life up to 200 hours or more Automatically self calibrates to neutralize background contamination Sensitive to R 12, R 134a, R 1234yf and other refrigerants High low switch for accurate diagnosis of both large and small leaks Variable intensity audible alarm plus flashing LED help pinpoint leaks fast Includes sensor, replacement filters, (2)