Conversion set for T4'20 to improve it towards T4'21 Aluminum Solid variation. Includes all necessary elements including aluminum solid framework, graphite top deck, human body upstops & battery power adj. width dishes, composite 4° c-hubs for human body upstops, composite bumper top owner brace, composite adj. electric batteries holders & backstops, springs, ECS drive shafts 52mm, aluminum steering dish 8mm, aluminum gear tensioner, aluminum engine mount, aluminum framework brace, aluminum right back suspension system system, holders with centering pin, metal solid drive shafts as well as other elements,