I have a few of them. My interest is position shooting and they work very well for training in 3p and prone. One is a Noptel and the other is a Scatt. Niether use a laser I believe they use infrared LED's.
In the case of the noptel there is a detector/transimitter unit that mounts onto the barrel of the rifle. The target has a reflector on it. At 50' or less the reflector can be reflective tape or a plastic reflector. For 50meters they use like a surveying reflector. The barrel mounted device plugs into a PC. The pc runs some software that displays an image of a target and as you move the rifle/pistol/cap gun/ or whatever the unit is attached to it displays your point of aim and records a trace. The shot is detected by the "sound" of the firing pin falling.
The Scatt Is very similar but has only a detector that mounts onto the barrel. The target assy, which comes with the Scatt, has some infrared LED's and the detector "sees" this. Generally, other than that it works much like the Noptel.
The Scatt tends to be more popular because it is cheaper. Both work very well. Many top position shooters practice with these devices. You can probable see more on them but googling "Scatt" or "Noptel".
There is actally a third unit that is called the RIKA. Pilington sells these. While Pilkington is a great outfit I would not own a RIKA. This was the first one I had and it was squirrely and I sold it.