GSL's Heavy-Duty GT-556 suppressor for 5.56mm NATO is rated for full auto fire and mounts with a Bi-Lock quick disconnect flash hider with standard1/2x28 TPI threads. The suppressor utilizes a standard HUB mounting interface allowing for a wide degree of compatibility with other aftermarket mounts. This model features an all-black finish and includes a quick-detach Bi-lock flash hider (1/2x28 TPI thread spec). This model features an all-black finish and includes a quick-detach Bi-lock flash hider (1/2x28 TPI thread spec).