Fully Enclosed Design: Heavy-duty cut-off switch made with an ABS plastic housing and copper-plated internal studs. The fully enclosed design protects the line from dust, corrosion and rain. This is the best option for adverse marine conditions. Prevent Over Discharge: This battery cutoff switch for 12‑48V DC systems is used to isolate and secure the electrical system; eliminates any power draw from the battery and safely disconnects the battery when the vehicle is not in use; provides a reliable way to turn off the