Most sites distribute power through a main conduit that leads to frame-mounted power distribution panels, one of which can be located at the top of the rack that houses the router. An AC power cord connects the power supply modules to the power distribution panel. Detachable AC power cords, each 4.5 m (approximately 14.75 ft) long, are supplied with the router and PSMs. The appliance coupler at the female end of the cord inserts into the appliance inlet on the AC power supply module. The coupler is type C19 (left-angle)as described by International Electrotechnical Commission (IEC) standard 60320, except for the CBL-PTX-LA-US-C20 model number, which has a C21 (left-angle) coupler. The plug end of the power cord fits into the power source receptacle for your geographical location.