Schumacher DSR138 - 24V 5A Automatic On-Board Charger Type_Filler the 4 contact positions are

the 4 contact positions are at 2

611221 - Associated Eqpt Front Panel 6007B W/Momentary Switch

(2) Self-Tapping Screws

- 300A Clamps

Also shows +/- Amps for easy diagnosis of current leakage problems

Schumacher DSR138 - 24V 5A Automatic On-Board Charger Type_Filler the 4 contact positions areDSR13824V 5A Automatic On Board ChargerConvenient for devices with difficult to reach batteriesThe 5A 24V Automatic Charger is an excellent solution for devices with batteries in difficult to reach spaces. This battery charger mounts on any flat surface with quick connect battery clamps, ring terminals, and 3 pin XLR 3 12C cables. It charges standard, AGM, and gel batteries with ease. The 5A 24V Automatic Charger features a heavy duty aluminum case