I've got an old Summit set up w/ the prussic, and first, I don't remember how to use it....just run the tag end through the loop, w/ the prussic against the tree? Also, I don't see how that will give me any length.

Coop, I tried what you suggest, but it pulls tight when I sit down. I think I'm gonna just bust one section that is sewn together and make it a bit longer....That should work.