Ko-ken Tools 3/8 Sq. Dr. Wobble-Fix Extension Bar set 32-250mm ABS Tray 6 piecesKoken PK3763 6 Wobble Fix refers to the section of the extension bar that holds the socket. Specifically, in reference to the flexibility of movement that a socket has when attached to an extension bar with this feature. Wobble Fix extension bars offer two different secure solutions for holding a socket in place. The Fix solution holds the socket securely and steadily on the extension bar permitting no movement. The Wobble solution permits movement of