Product review (5 stars): Knob rescued by tape!
When I first put this item on the mount, it spun around. I put a small piece of electrical tape on the post to take up the slack, but this didn't work because the tape prevented the knob from going on. I removed the tape and put the knob on again and turned it. The knob remained in placed and turned the post with no problem and has been working fine ever since. I suppose the slight amount of glue left on the post after I removed the tape solved the problem. Very happy with the item and the price.