CPW (tm) Refrigerant Gas Leak Detector Halogen R134a R410a R22 HVAC Detection Tool advanced leak detector. It comes with a reliable corona refrigerant sensor which has great sensitivity and excellent repeatability, and also features LED indicator light with 7-level leak alarm, visual and clear display. It will detect leaks as little as 0.1 oz/yr(3g/year) in R12,R22,R410a,R134a and other halogen refrigerant systems. Excellent sensor with high sensitivity, 0.1oz/yr (3g/yr) Single color LED display with 7-level leak alarm Tactile keypads make the operation more convenient.