This is the Master Airscrew 13x4 K Series Propeller. Designed for four-stroke engines, may also be used on two strokes. FEATURES: Constructed of glass filled nylon Wider blades and thinner airfoil sections make these props efficient and powerful for slower turning four-strokes INCLUDES One Master Airscrew 13x4 K Series Propeller REQUIRES: Installing on your aircraft SPECS: Length: 13" Pitch: 4 kpm02/07/2007 ir/jxs