OSS sku: 1677 used but in perfect shape. comes with just the brake and no shims etc.    Muzzle device length is 2.3 inches, length added to the barrel is 1.7 inches (on barrels with 0.6" threads) The Flash Hider-QD 556 is compatible with the HX-QD series (556k, 556, 762, 762 Ti, and Magnum Ti) and FLOW series (556k 556 Ti, 6k, and 762 Ti) suppressors. This flash hider is only compatible with VENTUM series suppressors when combined with the HUX HUB Adapter.