The inner joint of the early model (A120D4004F) has a fixed ball-type CV joint and the new model (B120D4004F) has a Tripod Plunging Joint.
The fixed ball-type consists of an inner ball race, six balls, a cage to position the balls, and an outer housing. Tracks machined in the inner race and outer housing allow the joint to flex. The inner race and outer housing form a ball-and-socket arrangement. The six balls serve both as bearings between the races and the means of transferring torque from one to the other.
Tripod plunging joints consists of a central drive part or tripod. This has three trunnion fitted with spherical rollers on needle bearings and an outer housing (sometimes called a tulip because if its three-lobed, flower-like appearance). On some tripod joints, the outer housing is closed, meaning the roller tracks are totally enclosed within it. On others, the tulip is open and the roller tracks are machined out of the housing.