EDEMO SilencerCo Single Port ASR Muzzle Brake 1/2x28 9mm Black AC2628 EDEMO5. For more great deals on Muzzle Brakes & Compensators by SilencerCo please browse our SilencerCo Gun Parts page. SilencerCo AC2628: Single Port ASR Muzzle Brake 1/2x28 9mm Black