I've used these frequently, to avoid being limited to suction-cup feeders at my windows. If I clean the window, dampen the suction cups, and give it a little bit to dry, it holds very well. Only really had a problem when I tried to hang something really heavy. Highly recommended! (Attaching picture - blue feeder is hung from one of these.)

I have 4 of these hangers. I have been unable to find them anywhere else. I have a hummingbird feeder hanging on one, a multi seed mixer hanging on another, an oriole orange hanger on another, my wind chimes on the last. They are not the prettiest hangers, but they are reasonably priced and never come down....unless the squirrels are on a rampage...lol....