One pair of 7mm scale machined stainless steel crankpins to fit Slaters loco driving wheels. Pin is secured to the wheel by an M1.6 flanged screw at the rear. Couplingrod is secured by a hex head M1.6 flanged screw. Soldering not required. Needs 14BA Nut Spinner to assemble. Also available 7MA049 Two Rod Crankpins for the crank axle of outside cylinder locos with inside valvegear (eg GWR Castle etc.).