This item is only useful when paired with a Laser, as it requires a laser being emitted into the detector to output a signal. It will only emit a signal when it detects a Laser going to the detector. This is useful for making scanning machines as it can help detect specific items as there is no signal at all when the laser is blocked. It is more effective to use a Signal Inverter as it will be outputting a signal when the Laser is being blocked, therefore it would make it easier to make circuits and machines.
The laser detector is able to detect lasers from other bases, thus making it easier for players to make cross-base machines. Please note that the height of plots of land is not the same, which makes the laser detector not receiving the laser signal possible.