Convenience: Direct fit and no modifications, connects directly to the top post negative battery terminal, no additional battery cables or terminal lugs needed, easily isolates and secures the electrical system. Operation: used for DC 12 - 24V systems, ON/OFF 2 positions, 275A continuous at DC 12V, 455A intermittent at DC 12V, 1250A momentary at DC 12V. Strong: ABS plastic housing, durably made for safe use. Extends the top post negative battery terminal to original size: standard top post negative terminal (17mm conical/tapered negative (-), installation space should be checked. Compatible: used for standard top post battery (19mm conical/tapered positive & 17mm conical/tapered negative). Can stand alone or be connected with other switches. Purpose: eliminate any power draw from the battery when the vehicle or boat is not in use, disconnects the battery safely, widely used for car, vehicle, RV, and boat.