This is the Great Planes ElectriFly Collet Cone Adapter 5mm-5/16-24. FEATURES: Aluminum construction, Silver in color Mounts on electric motors with a 5mm shaft and adapts them to a 5/16-24 diameter prop shaft Cone shaped spinner nut adds good looks INCLUDES: One 5mm Prop Shaft One Aluminum Knurled Prop Hub One Aluminum Prop Washer One Aluminum Spinner Nut (5/16-24 threaded) REQUIRES: Installation SPECS: Length: 1.82" (46.3mm) as assembled Length: 1.94" (49.5mm) shaft only Length: .94" (30mm) spinner nut only Shaft Diameter: 5/16-24 Spinner Nut Diameter: .71" (18mm) at the widest point COMMENTS: For the version without a spinner nut order GPMQ4966. jxs 02/21/07 ir/jxs