Sylvan Arms 30 Caliber Muzzle Device Long, 5/8X24 SA30QDL The Sylvan Arms .30 Cal Long Muzzle Device - 5/8x24 features 17-4 stainless steel construction with a corrosion-resistant nitride finish. This rugged muzzle device is designed to host the Sylvan Arms Warthog .30 Cal suppressor. This muzzle device can be used as a 3-prong flash hider and features a 5/8x24 thread pitch.