Higher tension The positive propellers are marked with L on the and need to be installed on the motor that rotates counterclockwise (the self-locking motor is white headed The 9450 propellers provides thrust and better power efficiency than the older making the quadcopter achieve significantly higher lift and thus more powerful The anti-propellers are marked with R on the and need to be installed on the clockwise rotating motor (the self-locking motor is black headed and easy to use product