I make my own as well. Get my supplies from a local arborist store. I use a locked Brummell splice to make the terminal loop and put a carabiner on it so when I get to the top I can throw it around the tree and clip in he main line. Another difference is that I use a kliemheist(sp) knot rather than a Prusic. It seems to slide a little better. The only real difference between the knots is the kliem is only load bearing in one direction, don't figure I will ever fall up a tree. I tie on a camping carabiner at the bottom and use the safety line as my pull up rope as well.