On the hand climber you can move around the tree and it takes a side load as long as you still have your foot pressing down and it is past the pivot point. If you move around far enough that you are pushing the climber away from the tree it slips. I have used it with a strap girthed to one side with a hook on the other and it held fine once tightened down no matter which way you pushed it. If you use the hand climber to climb up the tree it can be tough to strap the bottom to the tree. You could do it with a aider but it still requires a good bit of effort.