An assembly has a connector, a circuit board, a cable, a light pipe, and an outer casing. The connector has an insulating body with conductive terminals fixed therein. The circuit board is behind the connector, is electrically connected with two conductive terminals, and has two light-emitting elements. The cable has a plurality of wires, and the conductive terminal is electrically connected with the wire. An inside of the light pipe is formed with a first receiving cavity that receives the connector and the circuit board therein. The outer casing has first and second insulating casings which are latched to each other and are combined to form a second receiving cavity. The light pipe is received in the second receiving cavity and is partially exposed out of the outer casing. Light from the light-emitting elements emits outwardly via the light pipe. The cable extends rearward out of the outer casing.