Bridge helps assure sufficient signal strength throughout 3-wire systems. The Signal Bridge couples the command signal onto the 120V legs of the power system to ensure sufficient command signal strength throughout the command network. Use of the 6299 is recommended for all installations. The wiring diagram shows the proper method for coupling a typical residential 120/240V system. When used in the same DHC network as a 6201 system Amplifier, the 6299 Signal Bridge should NOT be in the same panel or within 10 feet of the 6201. Dimension of 6299 is 2.693' x 4.125' x 1.387'.