To suit .12 to .18 Engines only. Will not be suitable for other engines unless meets below requirements: Crankshaft output thread is 5mm in diameter (to accept 5mm thread flywheel axle). Kit includes: 2 shoe aluminium clutch with spring. 2 pin flywheel. Flywheel axle 5mm thread. Clutch housing 15 teeth includes 2 x 10x5x4 bearings (ODxIDxW). Images copyrighted by BlackSmith Products Ltd.