I don't use one. I would rather have the simplicity of being able to clip the release (scott little goose) directly to the string than fumble for the string loop. I'm now on my 3rd hunting season with this bow and have not had to replace my serving yet. For those of you who worry about wear on strings...it's not the string that's getting the wear, it's the serving. I can put a new serving on and tie on a thread nock in about 10 minutes or so...it's cheap and easy to do. All that said, if I were shooting for accuracy only I can see the advantages to a string loop, but I'm plenty accurate without it and when I'm out in the woods for a week at a time, the simpler the better.