The sling is great. The rubber piece holds the biner in place very very well. I've used this sling with other biners as well, not just the spirits. They aren't the lightest slings but they are very very tough, and if you break the little rubber piece you can order a bunch more from petzl for not too much. Go to a store and practice clipping with these versus other slings with the biners you are going to use. I recommend these to anyone.