Material: The shell is made of high quality plastic, copper terminals with iron hexagonal nuts for enhanced continuity, high temperature resistant, not afraid of falling, durable. Function: Used for the battery to isolate and secure the electrical system, eliminate all power consumption from the battery when the vehicle or boat is not in use, safely disconnects the battery. Additional protection: l The main battery switch comes with 2 keys and a weather cover, and the keys also cover the opening when in use, which can better protect dust and water entering the key hole. Size: The screw diameter is 8mm/0.31inch, and the installation aperture is 5mm/0.20inch. The battery switch is used for DC 12V, rated current: 300A (12V). Wide applications: it can be used as the opening key of various electrical devices such as strobes, chassis and fog lights, which can be used indoors and outdoors. Package dimensions 10.3 x 7.7 x 6.9 cm; 170 grams