Modified C-hubs with holes for mounting graphite human anatomy upstop with height adjustable place to regulate as soon as the body details the graphite stops. The C-hubs feature big openings for faster & easier assembly/disassembly of ECS. The entire ECS installation can be easily inserted/removed through the C-hub with no need for disassembly. The big spaces prevent collision of ECS with C-hub in severe crashes. Caster pre-set at 4. Medium rigidity for carpeting race. Usage with matching left-side C-hub #302364-M.