screws and screw, poor quality plastic.

I am disappointed by the quality and accessories such as screws, plastic wrist too hard and is generating significant vibration, on the edge of the unbearable. I can not withdraw from the shaft tip with the trimmer head.
In comparison with an average mark brushcutter cache accelerator is stronger, if used too, the screw passes through the plastic housing.
The pot was 5 6 minutes, and I preferred to end the use of this set.