BRNKL Boat Monitoring Laser Sensor 20ftThis laser sensor shoots an invisible beam that is reflected back via a reflector. When the beam is broken the BRNKL will receive this signal and generate an alert. This laser sensor is IP67 rated and can be placed outdoors. The beam is capable of reaching across a distance of 20ft (6m). The laser sensor can be mounted using the included mounting bracket or it can be mounted by drilling a small hole (19mm or 3 4?). Whats included: Laser sensor