This is the Great Planes ElectriFly Collet Cone Adapter 2.0mm-5mm. FEATURES: Aluminum construction, silver in color Mounts on electric motors with a 2mm shaft and adapts them to a 5mm 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 (5mm threaded) REQUIRES: Installation SPECS: Length: 1.42" (36mm) as assembled Length: 1.10" (28mm) shaft only Length: .82" (21mm) spinner nut only Shaft Diameter: 5mm Spinner Nut Diameter: .47" (12mm) at the widest point COMMENTS: For the version without a spinner nut order GPMQ4953. kpm01/16/2007 ir/jxs