This is a Rock River Arms folding front sight gas block. Rock River has been a solid maker of AR parts for decades. This folding sight post has three sling loops: bottom, right and left. It is recommended that you choose one, and probably remove the others, unless you just like it that way. The bottom has a Picatinny rail.
The RRA folding gas block is constructed of 4140 steel alloy with a Parkerized (phosphated) finish. The gas block is for barrels with a 0.75" gas journal. The gas block includes a tactical bayonet lug.
