Forged in the fires of Mount Doom" the new M4SD II (Mod 4) begins life as over ten inches of 17-4 stainless" tool steel" bar stock. We have found 17-4 to provide markedly superior wear resistance" as compared to softer high nickel alloys of good reputation in industry. The heart of the M4SD II suppressor is a billet machined chassis (tube body)" with integrated muzzle device bearing surfaces" which houses the internal components. The chassis provides a housing substantially stronger than the strongest tube materials currently available. Through extensive" costly and time intensive machining of the chassis" a tube structure of superior geometry is derived. The chassis is encompassed by a series of flutes surrounded by supporting structures affording enhanced strength to weight ratio- coupled with a 40% increase of surface area for unparalleled cooling. The M4SD II has surface area comparable to 7.62mm suppressors on the market. Reducing the internal operating temperature of the suppressor yields a superior product with a level of durability beyond that of current market options. Monolithic structure of the blast chamber and tube maximizes safety factor and provides maximum theoretical temperature transfer" allowing heat to normalize" mitigating the effects of erosion to baffle surfaces. Integrated at the request of elite tactical units" the included flash suppressor front cap further reduces flash signature in pursuit of suppressed superiority.