DJI 2170 Carbon Fiber Reinforced Folding Propeller for E2000 Tuned Propulsion System (2x Clockwise Blade) The 21-inch propeller is made of Ultra Carbon Pro, an advanced composite material, for lower rotational inertia in combination with high strength and stiffness. Their aerodynamic profile combined with optimized electro-magnetic design of the motor make the E2000 extremely energy efficient. REQUIRES E2000 - 2170 Folding Propeller Adapter Diameter/Thread Pitch: 21 x 7.0 inch (533 x 178mm) In The Box: Blade (CW) x 2; Screws pack x 1; Washers pack x 1 (Propeller Adapter NOT included)