This is one R/C Airplane 4.2x2 APC Sport Propeller by Landing Products. / / FEATURES: APC props are manufactured using a pultrusion process. This method / causes the fiberglass "fibers" to be oriented axially in 1/2" long / pellets, allowing for a higher fiber (60%) to resin (nylon binder) / density. Providing substantially higher strength and stiffness than / glass filled nylon. / The additional stiffness is beneficial to control of vibration / resonance response. / The higher strength allows the use of thinner cross-sections, / beneficial to weight and aerodynamic efficiency. / Competition proven. / Molded in Dark Gray composite material. / / INCLUDES: One APC Sport Propeller / / REQUIRES: ALL props require balancing (use TOPQ5700). / May need prop reamer, use GPMQ5005 (SAE) or FOXQ1520 (Metric). / / SPECS: Prop Diameter: 4.2" / Prop Pitch: 2 / Hub Thickness: N/A / Hub Diameter: N/A / Weight: n/A / Engine Shaft Diameter: N/A / kr4/2/02 / ir/kh