This is an APC 20x15E Electric Propeller. FEATURES: Composite construction, Gray in color Thin propeller designed ONLY for Electric use INCLUDES: One APC 20x15E Electric propeller with one each .128" (3.2mm), .158" (4mm), .197" (5mm) .237" (6mm) and .313" (8mm) locating rings for a more precise fit SPECS: Hole diameter: 1/4" Propeller diameter: 20" Propeller pitch 15 COMMENTS: Do not use with nitro or gasoline powered aircraft. jxs 12/04/06 ir/jxs