Avid's new and improved stainless steel 5x7x0.3mm clutch shim fits 5mm crankshafts which are used for all .12, .21, and .28 engines. We have made the OD smaller from our previous batch to 7mm and this prevents them from touching the seal/shield of your clutch bearing. They come grouped in a pack of 10 inside our famous doodad container.