Using these HQProp propellers is easy. Just attach them to your compatible device with the 5mm shaft. Make sure the CW and CCW props are installed in the correct positions as per your device's requirements. When using, avoid flying in extreme weather conditions like heavy rain or strong winds. For maintenance, regularly check the props for any signs of damage such as cracks or chips. If you notice any damage, replace the prop immediately to ensure safe operation. Store the props in a cool, dry place when not in use to prevent any warping or damage to the poly carbonate material.