Product Description Caliber: .5.56mm NATO; Construction: 17-4 PH SS / Cobalt 6 Blast Baffle; Decibel Rating: 134 dB; Full Auto Rated; Length: 23.5"; Weight: 3.6 lbs YANKEE HILL MACHINE CO Turbo Integral Suppressed 5.56 NATO 10.5in Upper Receiver Group (YHM-7125) at GritrSports $1100.99 Buy Now Check Price on Amazon Check Price on eBay