The Strike Industries Oppressor SF Blast Shield is designed for use with SureFire's Fast-Attach muzzle devices. The Oppressor SF has a Quick-Detach System making it extremely easy and convenient to install or remove from your firearm.To attach onto your muzzle device, first hold the blast shield and rotate the base counter-clockwise until it stops. Then, open the locking fork and slip the Oppressor SF onto your SureFire muzzle device and center the device by rotating it until it's stopped by the muzzle device's alignment notch. Once aligned, push in the locking fork and hold onto the blast shield while rotating the base clockwise until it's fully tightened. To remove, do the opposite: still hold onto the blast shield but rotate the base counter-clockwise to loosen it off of the muzzle device until it stops and then pull the locking fork out. At this point you will be able to lift the Oppresor SF off of your muzzle device. FeaturesOppressor Concussion Reduction DeviceQuickDetach Syst...