Quick view Troy Troy Industries Low Profile, Troy Sgas-a4l-00bt-00 Lowpro Gas Block Bk $31.15 The.750 low-profile gas block is made for rail systems that need to go over the gass block.Fits all m4 carbines and m16a2, a3 & a4 rifles.It is machined from hardened steel with a black oxide fiinish and are made in the u.Sa..Finish: BlackType: Gas... Compare Add to Cart