The DJI 1345 Self-Tightening Props for Inspire 1 is a two pack that features one clockwise (CW) and one counterclockwise (CCW) prop. The centers of the props are color coded to simply installation. Please refer to the user guide to ensure that you replace the CW prop with a new CW prop and a CCW prop with a CCW prop. Improper installation will lead to the props becoming unscrewed in-flight. These are specifically for the DJI Inspire 1 quadcopter and should not be installed on other aircraft.