Using the Greenlee 39839 pendant switch unit is easy. First, make sure it's compatible with your electric bender (it's made for part No. 555C). Connect it properly to start operating your bender. When using, always keep it in a dry place to avoid any electrical issues. After each use, turn off the switch and disconnect it if you're not using it for a while. For maintenance, clean it regularly with a dry cloth to keep it in good condition. If you notice any damage, stop using it immediately and consult a professional for repair.