This telescoping alloy-steel drive shaft was designed with high-strength construction to handle higher torque loads. The hubs have been heat-treated for increased strength. For additional durability, the ends were outfitted with 'blind bores' to a specified depth, rather than fully through-machined. The shaft is internally spring loaded, in order to accommodate an oversized hex shaft and to keep the components confined to the shaft. The moving components are protected by one single-bellow boot cover and one low-profile boot, to enable operation in a tight envelope. The above image is partially exposed for a better view of the joint and its components.