This is a Master Airscrew 12x7 Nylon Prop for Electric Motors. FEATURES: Designed exclusively for Electric flight. For direct drive or gearbox use Made of "glass-filled nylon for durability. Blades are wide and thin to provide the flex needed for hard landings Undercambered blades give great thrust and pull for superior perfor- mance. Bore size is a uniform 1/4" INCLUDES: One 12x7 Nylon Propeller for Electric Motors. SPECS: Hole Diameter: 1/4" (6.3mm) Propeller Diameter: 12" Propeller Pitch: 7" COMMENTS: These props are only for Electric motors. rda7/26/06 ir/jxs