Conversion set for T4'20 to convert it to the T4'21 Aluminum Flex edition. Includes all necessary components such as for instance aluminum flex framework, graphite top deck, body upstops & battery pack adj. width dishes, composite 4° c-hubs for human body upstops, composite bumper top owner brace, composite adj. battery holders & backstops, springs, ECS drive shafts 52mm, aluminum steering plate 8mm, aluminum belt tensioner, aluminum engine mount, aluminum framework brace, aluminum backside suspension system, holders with centering pin, metal solid drive shafts and other parts.