This is the APC 10x3.8 Slo-Flyer Pusher Electric Propeller. FEATURES: Foe electric and Park-Flyer type aircraft Pusher propellers molded in the opposite direction from standard propellers, they are designed for airplanes with the motor facing backwards in the rear of the plane, PUSHING the airplane forward Lightweight molded nylon construction reduces rotating mass for higher output and longer life Reinforcing fibers help maintain true, constant pitch at any RPM INCLUDES: APC 10x3.8 Slo-Flyer Pusher Electric Propeller 0.236" (5.9mm) and 0.188" (4.8mm) locating rings Instruction sheet REQUIRES: ALL props require balancing (use TOPQ5700) May need prop reamer, use GPMQ5005 (SAE) or GPMQ5007 (Metric) SPECS: Length: 10" Pitch: 3.8" COMMENTS: Slo-Flyer props cannot be used on glow or gasoline powered engines jxs 12/05/11 ir/jxs