Shop › AERO ADJ LOW PROFILE GAS BLOCK .625 AERO ADJ LOW PROFILE GAS BLOCK .625 $71.99 Aero Precision Low Profile Adjustable Gas Block, Fits AR15 with 0.625" Barrel, Nitride Finish, Black APRH101613C Add To Cart Added! Aero Precision Low Profile Adjustable Gas Block, Fits AR15 with 0.625" Barrel, Nitride Finish, Black APRH101613C