The force Grumpy, actually meant by 10 "propeller balance with me, is total nonsense. The magnets are either rusted or have a patina, which make a smooth, straight clamp impossible. In addition, the frame is so tight that the propeller can not really turn - it's more of a terminal than a turn freely. Who has a hex screwdriver with 2 mm diameter, the situation can be improved though. Really good product is not even.
