CNC-machined 50mm ECS driveshaft made from world-renowned top-secret HUDY Spring Steel. This race-quality driveshaft is a spare part for #305325 Equalized Corner Speed (ECS) Driveshaft 50mm - Hudy Spring Steel (1), exclusively manufactured by HUDY. Driveshaft diff end has been strategically lightened to reduce rotating mass without compromising strength.