This is the APC 13x10F Folding Composite Prop for use with Electric motors. ****Not for use with gas or glow engines**** FEATURES: Gray composite construction blades that require assembly onto a propeller hub (hub not included). INCLUDES: Two composite prop blades One assembly instruction sheet REQUIRES: Prop Hub (SEE COMMENTS) Balancing SPECS: Length: 13"(330.2mm) Pitch: 10 COMMENTS: If using a 40mm spinner the individual would need APCQ4390 hub If using a 30mm spinner use part number APCQ4385. wm 8/20/04 ir/jxs