The negatives: the screws provided (actually little screw) are a joke - well, I've previously read and therefore bought 12 cm long metal frame anchor, so they keep well in my brick wall. Before my 25 kg punching bag hung on, a quick check on stability -> OK! But at the latest when I began to bang on the bag to get ready so that vibrate with short, quick strokes, the whole mount began to swing. The arm is, after all, an 60cm boom - at the end, he moves well 2cm left and right.
I do not think that it is up to the wall or on the screws - rather to the fact that the holder down too short cross stabilization has with only 2 screws - they would have a just as long as above with 4 screws, the stability would be better ,
The fact is that it is too uncertain and I will now look at a punching bag.
