These are the 7x4F Folding Propeller Blades from Advanced Precision Composites. For use on Electric powered aircraft only (not for glow engines). FEATURES: Gray composite propeller blades that assemble onto a propeller hub (hub not included, see REQUIRES). Comes in a bag attached to a header card INCLUDES: Two composite propeller blades One instruction sheet REQUIRES: 45mm prop hub and hardware for assembly, use APCQ4390. Hand and eye protection when operating propeller. ALL props require balancing (use TOPQ5700) SPECS: Diameter: 7" Pitch: 4 kpm12/13/2006 ir/jxs