This might be just a dud I got, but the swan arm is very weak, and can't support even a SM57. It bends under the weight. As I mount this on the side of a 212 and want the mic to be help horizontally from the side that is totally unusable because of this. Tried a swan arm from K&M, which was much thicker and very, very rigid in comparison.
If you want to support something like a Sennheiser 906 this might work, but nothing else.
But as I said, mine might have been a dud, with a sub par swan arm.