Pretty good with a few faults. The channel should have been milled slightly wider to accept the diameter of a swivel stud and gun screws. Obviously, the swivel stud will block any attachment wanting to slide along the rail, but it would be nice to use a swivel stud at the end of the rail for a sling (instead of ordering some other needlessly expensive attachment to attach to the rail for your sling). These are annoying issues for an expensive block of aluminum. The bolts that come with the rail seem proprietary. For starters, they are way too long. You are expected to grind them down, I guess. And since the channel isn’t wide enough for a standard gun screw head, you’re otherwise searching hardware stores for an appropriate length bolt with the appropriate sized head (both in width to fit the channel and in height so the bolt head is not protruding from the channel).