Assembly instructions:

1. Get all parts ready (Power system, propeller saver, nuts, washer and rubber band)
2. Screw one nut all the way down the drive shaft
3. Insert another nut into the center hole of propeller saver
4. Tighten the propeller saver on the drive shaft
5. Put washer onto the drive shaft
6. Put on the propeller
7. Use a rubber band to fix the propeller in the method like shape 8 or so called "butterfly"