This is a new product from a local company, 87 Industries - the gas block itself is a very well made 17-4PH SS, low-profile arangement, the couple I was able to see fit on a 0.750 pin gauge perfectly!
The trick to these is that small pocket milled out on the side... at the bottom is a drillpoint dimple for aligning and starting a drill - this allows anyone to drill to pin their own gas block installation. Even with a cheap-ass drill press (or even a cordless hand held drill) you can drill a hole that clips the barrel perfectly. The included cross pin is splined to ensure a tight fit and the kit comes with the GB, drill bit, knurled set screw, allen wrench and lock-tite.
https://www.m4carbine.net/picture.ph...pictureid=3333

