Eathtek Replacement Portable Freon Halogen Refrigerant Gas Leak Detector Tester with High Sensitivity R410A R22 R134A HVAC Tool 7 Level Alarm Health and Safety Assistant Excellent sensor with high sensitivity,3g/yr (0.1oz/yr) Detects All KINDS OF halogenated refrigerants Flexible stainless steel probe reach to almost any tight space, Single color LED display with 7-level leak alarm Tricolor display of battery voltage(Green, Orange & Red)