This is a 14x8.5E Electric ONLY Composite Propeller from Advanced Precision Composites. FEATURES: Gray composite one-piece construction Five adapter rings that adapt to different motor shafts INCLUDES: One composite propeller Five composite adapter rings for motor shaft diameters of 0.128" (3.2mm), 0.158" (4mm), 0.197" (5mm), 0.237" (6mm), 0.313" (7.9mm) REQUIRES: ALL props require balancing, this is VERY important, use TOPQ5700. May need prop reamer, use GPMQ5006 (SAE) or GPMQ5007 (Metric) SPECS: Diameter: 14" Pitch: 8.5 Hub inner diameter: 0.25" (6.3mm) COMMENTS: For use with Electric motors only. Do not use with nitro or gasoline powered engines. kpm12/06/2006 ir/jxs