Four 4-pin JST ZH connectors to connect CAN bus to four Tool Boards. Four pairs of 2-pin jumpers to bypass unused tool board CAN connectors. CAN bus termination jumper, for use if the CAN_OUT RJ11 port is not used. Two RJ11 connectors for CAN bus in/out to connect to Duet 3 main board and expansion boards. Four 2-way JST VH connectors for power out to tool boards, individually fused (5A fuses supplied).