I made myself a set of STL's copying the design on Whoopieslings.com . They are .1.7 Zing It. Initially they appeared to work wonderfully. I ran into an issue this weekend. I got caught in a thunderstorm and found myself needing to tighten my tie outs. Actually I had the tarp in baker hut mode and needed to lower it, hence needed to shorten the tie outs. Once wet, the prussiks got almost too tight to slide. I had to really yank on those lines while holding the knot for them to budge. I even have a small cut from the line digging into my finger. Once the weather improved I experimented with the prussiks. Maybe I have too many wraps. They are 3 wrap prussiks. I tried 2 - nope wouldn't hold on that slippery line. So now I seek a new method of tightening the lines.