Have the brackets used for my Canton Plus GX.3. The boxes have a weight of 1.7 kg, and I see the problem. The maximum according to the manufacturer Weight of 3.5 kg, I think designed for very optimistic because the brackets already come with my boxes to their limits. The weakness here is the ball joint. I would advise anyone before buying rates again to check the weight of the boxes to be mounted so, because the holes are drilled only once it is too late. For the manufacturer's instructions have gone out again lightly for me, I have to deduct two points. What I really liked is that man can hide the cables well and that is also processing in this price range more than ok.