Battery isolator switch with removable red plastic key. A simple to fix device to isolate the electrics in a car or boat. Can stop the battery from running down in an infrequently used car or boat. Removing the key makes the vehicle difficult to steal. To allow an alarm to function and maintain the radio code, a 3 amp bypass fuse can be inserted between the terminals. This will immediately blow if the starter is used with the isolator in the off position. Complete with one key and waterproof cover. Click for spare keys