I just purchased a new hunters view silver condor lite, it came with a strap to put on around the tree, this strap is not part of the safety harness and it goes right under the top cable and fastens to the stand. I have used climbers before and never had to put an extra nylon strap around the tree. What is the purpose of this, and do I need it? By the way this climber is no diffrent than any other and dont see what this strap would do