This is a 17x6 IMAC Aerobatic composite propeller from Advanced Precision Composites. FEATURES: Gray composite one-piece construction Comes in a bag attached to a header card INCLUDES: One 17x6 IMAC aerobatic composite propeller REQUIRES: ALL props require balancing, this is VERY important, use TOPQ5700. May need prop reamer, use GPMQ5005 (SAE) or GPMQ5007 (Metric) SPECS: Diameter: 17" Pitch: 6 Hub inner diameter: 0.30" cdh8/26/03 ir/jxs