The Yocto-RangeFinder is a USB distance sensor (range finder). It works by measuring the time-of-flight of an infra-red laser beam that reflects on the target.

Be aware that this small and relatively cheap module, using a quite harmless laser, does not pretend to be a true telemeter that you could use to measures distances with a millimeter accuracy. Its accuracy is limited, and the detection range depends on the environment. You can find tables describing the expected accuracy depending on the surrounding conditions in the section of the documentation entitled Working principles and limitations.

Measurements can be read directly via USB or stored on the device internal flash for later retrieval when connected again by USB.

This device has been designed so that the sensor itself can be moved away from the USB part by a few meters: simply split the board into two parts and use a 4-wire cable between the two parts.