When I've used it for a flip-line the weight of the climbing line tended to pull down and close the loop. It just seemed awkward. But, then again, I'm not that great of a climber. I use them when trimming palm trees (helps minimize gaffing them 'cause you can decend on line). What I do is climb with a regular flip line, then attach friction saver w/climbing line, trim tree w/ handsaw or chainsaw, then decend on climbing line. It really helps when trimming clumps of trees, just climb the tallest one first.