This is a 6x4E Thin Composite propeller from Advanced Precision Composites. For use on electric powered aircraft only (not for gas engines). Features Gray composite propeller blades that assemble onto a propeller hub. Comes with two adapter rings that adapt to different motor shafts. Comes in a bag attached to a header card. Includes One composite propeller Two composite adapter rings One instruction sheet Specifications Diameter 6" Pitch 4" Hub inner diameter 0.25"