Automatic Power Transfer Switches Automatic Power Switches Automatically switches any load from power supply to battery in the event of generator or power supply failureAudible and visual alarm in the event of generator or power supply failureAlarm silence switch and test button30 amp contactsEnclosure is 10″W x 8″H x 4″DAvailable for 12, 24 VDC and 120 VAC More Info... Model JB-1-12AC Model JB-1-NLAC