Fieldpiece Heated Diode Refrigerant Leak Detector - SRL8 Triggers on all CFCs, HFCs, HCFCs and blends. More sensitive to some refrigerants than others. 15-hour rechargeable, user replaceable battery. It lasts almost two full workdays on a single charge (if your hunting down leaks all day). You can also use it while it's hooked up to the wall or vehicle charger. Filter system helps protect the sensor from moisture and other contaminants. The sensor is connected to the body at the other end of the snout. The filter is at the tip of the snout. If you accidentally hit some condensation or oil, the filter swells, shutting off the pull to the sensor and protecting it from failure. Manual or automatic zeroing. It auto zeros every two seconds until a leak triggers the sensor. After that you can manually zero the detector to help further pinpoint leaks. Up and running in 30 seconds. Some heated elements and corona discharge units take much more time to warm up. UV dyes can take several hours to travel through a running system and can degrade system components.