The reason for listing it as junk is that the first level (weak) of the counter-balance, out of the 0-3 level range, doesn't seem to be working properly. There may be other issues I haven't noticed. Until recently, I was using a 600mm f/4 super-telephoto lens with the third level (strong) without any problems. Please note that the lens plate is not a genuine one. I am listing this as junk.