The largest ones I have seen only went up to about 22". I have one that goes up to 20. A 20"tree is pretty big. I would like to find a climber that you can adjust while IN the tree. I too like to go really high and I find that a lot of times when I set the climber so that I can climb with it at the bottom of the tree then the tree gets too small and the climber starts to angle down before I get as high as I like. If anybody knows of one that can be adjusted while in the tree I would be interested to know about it.