Description: This is a dual function hexagon ball type universal joint that can be used as a wobble and straight extension bar. This tool allows you to extend the socket when turning the bolt nut in deep areas. A dual function dual type that can be extended to 20° as a straight 2.1 inches (53 mm) extension bar when inserted into the deep. Product Specifications: Drive: 3/8" DR (9.5mm) to 1/2" DR (12.7mm) Total length: 2.1 inches (53 mm) Material: Chrome molybdenum. Surface Treatment: Mirror Note: Please do not add two or more joints.