Main function: The battery protection switch safely disconnects the battery circuit to prevent parasitic drain and reduce power consumption. Material and durability: ABS shell with a copper plated male thread stud provides hardness, good toughness, and corrosion and wear resistance. Easy operation: Turn the knob on the battery control switch to disconnect or reconnect the battery for convenient control. Compatibility and applications: Designed for batteries in passenger cars, trucks, construction machinery, ordinary RVs, yachts and marine boats, with broad applicability. Use scenarios: 1) Parked passenger car or truck during longterm storage to prevent battery drain. 2) Idle construction machinery to protect the battery between jobs. 3) RVs or yachts with house/engine batteries to quickly isolate power when not in use or when moored.