This tool is used to replace worn out ball joints. Also can be used to remove CV drive shafts on FWD vehicles. The opening is 15/16" and the length is 11-7/8".. This heavy-duty tool is drop forged and heat-treated for long use. Skin-packed.. Shipping wt. 1 lb. 8 oz. Ball joint separator is heavy-duty and used for separating the ball joint from the steering knuckle. Insert fork between parts and strike tool with a hammer to separate.