Look into a rope and Prusic knot system like Summit has with their harnesses. It is much easier to use and allows much more freedom of movement IMHO. Or you can make your own by getting some climbing rope.

Here is the link to the rope and Prussic you can get from Summit and you can also get a caribiner to connect it all up for another $12.

http://www.summitstands.com/productd...aspx?id=329147