The SoundGuard suppressors are developed in collaboration with KGM Suppressors and feature their innovative baffle designs for improved sound suppression while maintaining accuracy. The suppressors thread onto standard 1.375x24 TPI HUB adapters making installation quick and easy across a variety of firearms and configuations. The SG-556 is designed for use with .223 Remington or 5.56x45mm NATO ammunition. Included is a 1/2x28 TPI direct thread HUB adapter along with a non-proprietary flat wrench tool for quick and easy installation. *Sound reduction ratings are approximate based on measurements by the manufacturer and may vary depending on firearm setup and environmental factors.*