The DJI CPPT000195 Self-Tightening Propeller Set for Phantom 3 (Pro, Advanced & Standard) is a set of two 9" propellers for the DJI Phantom 3 quadcopters. It features one clockwise (CW) and one counter-clockwise (CCW) rotating prop. Be sure to replace the original prop with a new one that has the same rotational direction. Improperly installed props will loosen, detaching in flight. For instructions, please refer to your Phantom's User Guide. Second generation airfoil designed with computational fluid dynamics (CFD). Self-tightening design avoids prop becoming loose during operation and potentially flying away. Integrated nut molded into the propeller.