This is a 9x4.5E Thin Composite propeller from Advanced Precision Composites. For use on electric powered aircraft only (not for gas engines). FEATURES: Gray composite one-piece construction Comes with five adapter rings that adapt to different motor shafts Comes in a bag attached to a header card INCLUDES: One APC 9x4.5E composite propeller Five composite adapter rings REQUIRES: ALL props require balancing, this is VERY important, use TOPQ5700. May need prop reamer, use GPMQ5005 (SAE) or GPMQ5007 (Metric) SPECS: Diameter: 9" Pitch: 4.5 Hub inner diameter: 0.25" cdh8/26/03 ir/jxs