Contains a pair of detailed (3D-Printed) 20mm Colt cannon barrels with muzzle brakes compete with accurately placed and sized vent holes. Barrels are deeply drilled out. For most A-4C and later Skyhawk kits, with the exception of IAF aircraft, which are fitted with different model cannons. A very simple and highly visible upgrade. Designed by Craig Sargent. [A-4E]