Control Box. Four circuits can be powered on or off, all 4 from a common power source. This control box is for dividing a track or accessory circuit into 4 different circuits, each with two connections. For example, 4 storage sidings in the same track circuit or 4 users in the same accessory circuit can be turned on and off. The control box comes with 8 sockets on the back and a plug on one end and a socket on the other end. All of the connections are for the new plugs from the 71400 sets. 8 appropriate plugs included. Dimensions 80 x 40 mm / 3-1/8" x 1-9/16". For example, you can use this box to power/unpower lights, or portions of track. This box is the new replacement of the 7274 Control Box. The only difference is the hook-ups for the plugs. The new plugs fit this box. It also replaces the good old Marklin 7210 Requires the new Marklin 66366 power supply.