Low Profile Steel Gas Block fits all M4 Carbines and M16A2 – A3 and A4 rifles with .750 barrels. Replaces front sight and requires 10″ or longer free float handguard for enhanced reliability.
 
For your safety, Trinity Force recommends this part be installed by a competent, qualified gunsmith/installer with an understanding of the weapon platform that the part is being installed on. Always make sure the firearm is unloaded and pointed in a safe direction when working.