Stahlwille torque wrenches have blank ends to accept interchangeable insert tools sizes 9 x 12 or 14 x 18 the unique triggering cam mechanism means that the internal mechanism is only under load when force is applied to the wrench there is no need to back the wrench off after use the internal mechanism is extremely resistant to mechanical wear and is protected against dirt ingress suitable for use in the clockwise or anti clockwise direction simply by turning the wrench and insert tool over the