.12 to .18 Nitro Engine 2 Shoe Clutch Kit 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) Clutch measures 21.02mm diameter x 7.55mm wide This is a smaller than usual clutch kit that will not perform well with 26mm clutch housings. Suited to 24.6mm clutch housings (internal diameter). Kit includes: 2 shoe aluminium clutch with spring 2 pin flywheel Flywheel axle 5mm thread - 3mm threaded metric screw and washer required (not included)