The RJ11 telecommunications connector is the standard phone jack. The unit consists of a small, clear plastic sleeve that crimps onto the end a 4-lead phone cable to connect the cable wires with the contacts in the jack. The RJ11 is keyed to fit a phone socket and has a small plastic spring clip to hold it in place. You need a special crimping tool to install an RJ11 phone jack. Similar in appearance to a pair of wire cutters, the tool both strips the wire of insulation from the cable and then fastens the jack to the cable.
Open the crimping tool. Place the end of the phone cable squarely between the cutting blades of the crimper tool. Squeeze the handles together to cut the end of the cable.
Re-open the crimping tool. Insert the cable to the proper distance into the stripping slot in the tool. Squeeze the handle again to strip the insulation from the cable wires. With the cable still in the tool, relax your grip on the tool and pull the cable from the tool to remove the stripped insulation.
Insert the exposed wires at the end of the cable into the opening in the end of an RJ11 phone jack. The wiring should be black, red, green and yellow from left to right when looking down through the top of the jack with the opening of the jack facing toward you. Push the outer insulation into the jack.
Open the crimping tool again. Insert the end of the jack with the wire inserted into the RJ11 crimping cavity on the side of the crimping tool. Squeeze the handles firmly to crimp the jack onto the wires.
Open the crimping tool to release the finished phone jack and cable.