A wrench for a installing a support member for a prosthesis including a body, rotating cylinder in the center, and cap. The cylinder has a cap on one end and a driver on the other. The bottom of the cap has radially disposed ridges and grooves. The body has bores therein, each with a spring and rotatable ball. Each ball protrudes from a bore and is in contact with a groove.When the cap is rotated each ball is in a groove and the cap, body and driver rotate together, to install the support member. When a maximum torque is obtained, each ball is depressed causing the cap to rotate preventing further installation of the member.A kit includes several wrenches and drivers, each wrench having a different maximum torque and each driver having a different tip configuration.
