Advantage Arms 1.75×2.5 Stainless Steel Suppressor, a Super Compact AR-15 Suppressor. Measuring just 2.5 inches in length, this compact powerhouse brings your AR-15’s noise levels into a far more manageable range. When paired with an 11.5-inch AR-15 pistol, it reduces sound from over 179 dB down to just 150 dB. Built from rugged stainless steel, this suppressor is made to last a lifetime-and it’s backed by their lifetime warranty.