Thanks for the link.
I might have to consider getting 2 of these. Though I'm questioning what they use for sensors and where they are placed on the plane.
Most likely, the sensor is a 'light meter' of some sort that measures red light. According to the instructions, one sensor (the 'gun') is placed either on the leading edge of the wing or at the tip of the nose. The target sensor is on the trailing edge of a wing or at the end of the fuselauge.