Very niche piece of kit, but works wonderful when it works. - Kinetic Development Group Kinect MLOK Rails

Because the MLOK standard that Magpul designed only addresses the outer dimensions of the slot and NOT the depth of the slot relative to the rail you WILL get fitment issues of these devices on some rails. Most notably the polymer handguards from Magpul itself. This is because in order for the rail to withstand stresses from weight bearing accessories like bipods or vertical/angled foregrips, they had to beef up the thickness of the polymer. This will prevent the locking tabs of the Kinect from engaging and expanding out correctly. I found this out right away with I bought a 3 slot piece as soon as it came out last year.

So I just dremeled the polymer off on the sections I wanted this device to go to.

I have heard unverified reports of it not working with some aluminum rails however, but Opticsplanet has pretty decent customer service so I wouldn't be too worried about it.

If you're lazy like me and I don't want to use a screwdriver all the time at the range to get things on and off your gun, these Kinects are the ticket. However they aren't cheap so I would plan out what accessories you truly need mounted in this fashion and buy conservatively.