You are looking at a pre owned 20" precision AR-15 build. This rifle has a Wilson combat receiver with a Giselle automatics H1 buffer, Sig Sauer Romeo5 red dot, and a 20" heavy profile barrel that starts at 1" in diameter and reduces down to .75" at the gas block. I am unsure of the brand of the barrel. The gas system is a rifle length gas system. This rifle has a Lantac muzzle break. There is absolutely no play in the receiver set. This rifle has no choice but to be a tac driver based on what I am seeing here. The rail appears to be a generic type Mlok rail which is the cheapest part of this rifle.