You can find the Griffin M4SD Flash Compensator 5.56 here.

The Griffin Armament M4SD Flash Compensator combines the functions of a Flash Suppressor, Muzzle Brake, and a Tactical Compensator into one package. The M4SD II Flash Compensator achieved a perfect 5 out of 5 in National Tactical Officers Association testing to achieve the rare, coveted NTOA Gold seal of approval granted to devices that achieve perfect evaluations. The M4SD Flash Compensator is pre-drilled and 2.25" in length to bring a 14.5" barrel up to 16" when permanently attached for non-SBR, M4 carbine builds. The M4SD Flash Compensator is compatible with Griffin M4SD suppressors and provides a sacrificial baffle to increase the service life of your silencer. Includes shim set and over-travel stop washer.

Specifications:

• Caliber: 5.56mm
• Diameter: .863"
• OAL: 2.25"
• Weight: 2.9 ounces
• Materials: 17-4PH Stainless Steel
• Finish: Black Oxide
• Attachment: 1/2X28 Thread
• Over-travel stop tab should be positioned at the bottom of themuzzle device (6 Oclock).