Offer efficient and stable propulsion for the aircraft. 1. The propellers for adjacent motors come in clockwise (CW) and counter-clockwise (CCW) orientations. Propellers marked with orange should be attached to the motors on arms with corresponding orange markings, while those without markings go on the unmarked arms. 2. It is recommended to use the screwdriver provided in the package for installation and removal. Using a screwdriver of the wrong size could result in stripped screws or inability to disassemble. 3. For flight safety, propeller screws should be replaced alongside the propellers. Offer efficient and stable propulsion for the aircraft.