This kit comes with all parts required and includes cables and connectors. The driver's display shows distance (max 2.5M) via a 7 segment display, left & right LED bar-graphs and audible alarm.  The distance displayed is surprisingly accurate and has a 100mm resolution. Paint and moisture don't seem to bother the sensors and the radar will work with 1, 2, 3 or 4 sensors.

Parts list....
Control box.
4 Ultra-sonic sensors cables.
Driver's display and cable.
Power supply cable.
Hole saw (drill).
Double sided tape.
Instruction booklet.