The Troy Micro BattleSight greatly enhances weapons such as the new IAR, the Sig Sauer 556® Pistol and Carbine, POF 416®, FN Scar®, Robinson Armament XCR®, Heckler & Koch 416® & 417® and other weapons with raised top rails.
we need a Y or N.. enhancing doesn't tell us if it fits on the gas block of the Sig 556 piston operating platform.
These work out perfectly for me on AR platform running free floating Keymod or M-Lock handguards with modular, (or hardware attached), picatinny rails. They are a lower overall height than the standard Troy folding battle sights, so they allow for an excellent low solid cheek weld which is my preference. They can mount to a railed gas block as well, if it is the same height as the rail on the upper receiver where the rear sight mounts. If your gas block rail is lower than the receiver rail, you may be able to run the standard front, and micro rear, for a Front Sight-Troy folding battle sight (standard height), and for a Rear Sight-Troy Micro folding battle sight. The micro sights co-witness with Vortex Spitfire with spacer block removed. And also I believe with an earlier version SPARC with removable spacer block on mount? But I am not sure about there being a SPARC model with removable spacer. (The newer models of each use a AAA battery below the sight in the mounting block area so they cannot be lowered in that manner).