The joints use ball mechanisms to provide a fluid motion/rotation. They are connected by mutually engaged hexahedrons, this innovative connection disperses the load across the whole outer circumference of the tool. Allows 60 degrees of rotation Input Drive Size: 3/8" Drive Shape: Square Length: 65mm Type: Universal Double Joint Output Size: 3/8" Output Shape: Square Product Dimension (Refer Line Drawing Image): D Size: 17mm L Size: 65mm