HKII-4525 Shaft Kit (6mm 35mm)Product Description The Scorpion HKII 45 series motors are built with 10mm hardened steel shafts that will last through countless hours of use. However, occasionally they can wear out, or you may prefer another size of shaft specific for your model. We offer factory replacement shafts for all the HKII 45 series Scorpion Helicopter Motors. This shaft kit is for the HKII 4525 series motors, and is the SHORT shaft option. The pinion end of this shaft is