The standard AK Railed Gas Tube provides a lower 1/3 co-witness sight picture with Aimpoint micro red dot sights. The internal profile is made to the same profile as the standard AK gas tube.
Midwest Industries, Gas Tube, Fits AK, 6.75″ Length, Mil-spec Top Rail, Black Finish
-6061 Aluminum and 4140 Steel
-Mil-Spec Top Rail