Using these Gemfan 35mm 3 - blade propellers is easy. First, make sure your motor is the 08028, which is the adaptive motor for these props. Then, carefully insert the 1mm shaft of the propeller into the motor. You've got 4 clock - wise (CW) and 4 counter - clockwise (CCW) props, so use them according to your aircraft's design. When it comes to choosing a color, pick the one that suits your style from Clear Blue, Clear Gray, Orange, or Milk White. During use, fly in an open area to avoid hitting obstacles. If the propeller gets dirty, you can gently clean it with a soft cloth. Also, check for any signs of damage before each flight. If you notice cracks or chips, it's time to replace the propeller. Store them in a cool, dry place to keep them in good condition.