This is the Great Planes ElectriFly Collet Prop Adapter 1.5mm-3mm. FEATURES: Aluminum construction, silver in color Mounts on electric motors with a 1.5mm shaft and adapts them to a 3mm diameter prop shaft INCLUDES: One 3mm Prop Shaft One Aluminum Knurled Prop Hub One Aluminum Prop Washer REQUIRES: Installation SPECS: Length: 0.83" (21mm) Shaft Diameter: 3mm COMMENTS: For the version with a spinner nut order GPMQ4982. jxs 02/21/07 ir/jxs