This heavy weight full mortise hinge is recommended for use on high frequency and/or heavy wood or metal doors in schools, hospitals or other public buildings where heavy traffic is experienced. Heavy weight hinges should be used on all extra heavy doors or those exposed to high frequency use. Each hinge features concealed plug connectors that eliminate the need for separate or exposed wiring. Standard connectors make installation quick and simple. Brass eyelets add protection and durability. Electric hinges allow a constant flow of current from the power source through the hinge to electrified door hardware. No external wires can be seen, eliminating tampering and improving the aesthetics of the door opening. For 4 amp continuous @ 24 volts AC or DC per circuit, 28 gauge multi-strand wires are used. An 8 position connector is used for QC4 and QC8 wire hinges. An 8 position and a 4 position connector is used for QC12 wire hinges. Electric hinges should be installed in the center position on the door. Installation instructions are packed with each hinge.