APC Slow Flyer Electric 12x3.8 Prop
APC Slow-Fly Electric Series props offer high thrust at low RPM, and offer great value for your electric powered models. The center hole of the prop is designed to accept a reducing bushing to fit your propeller shaft. Included with the prop are 2 bushings to fit 3/16" and 6mm prop shafts.
According to the widely accepted Maximum RPM formula of 65,000/D for APC SF-Series props, the 12x3.8SF prop should not be used over 5,417 RPM.