Well, I tried the cut aluminum arrow toggle option on my tree straps with whoopies goin to the blackbird. I used the proper marlin spike hitch method with the whoopie on the knot. Worked well for my 10 minute test until I pulled out the toggles to see both had collapsed. Just thought I'd informed people who want to try it to be sure to test it first. They definitely have a limit to them, i weigh 205. I'm stickin to my Petzl carabiners.