This control box is for turning 4 different track or accessory circuits on and off. For example, power can be controlled in 4 storage sidings in 4 different track circuits. The unit comes with 8 sockets on the back. All of the connections are for the old 2.6 mm / 3/32" plugs and sockets. Dimensions 80 x 40 mm / 3-1/8" x 1-9/16".Package contents 5 pieces.