4 Sensor rear only kit no display just audible tones. The system can be programmed to ignore tow bars or spare wheels. This is our value 4 Sensor kit branded Ebat which comes with 3 years warranty. The sensor hole size is 18.8mm in diameter and they have detachable cables and a 6 degree angle of tilt. The power loom and buzzer are a one piece cable. A hole cutter is included in the kit.