1/5 scale upper main mechanisms with 1/2" diameter oleo struts which rotate 90 degrees. Strut diameter can be increase to 5/8" or 3/4". Axles installed at angle specified by manufacture and comes with a complete large air system included! See part number 1400 for large air system description. For realistic retraction and extension gear speed, look at our Deluxe 4 Way Valve. Order 1410E when ordering the gear and save $$$$.