Setting up a gravity filter usually means tying a knot in cold or dark conditions, then untying it the next morning. The Hang System gets rid of the knot. A PA12 cleat clamps onto 1 yard of 1.8 mm reflective nylon cord: loop the cord around a branch, feed the tag end through the cleat, and the line locks under load. One hand, no knots. Designed around the workflow of a gravity water setup: clip the cord onto your dirty water bladder (Cnoc Vecto, Platypus, Evernew), which feeds your filter, which feeds your bottle. Total system under 10 g, rated to about 45 lb. The same 1.8 mm cord is sold by the spool as Reflective Cord; the Carbon Fiber Spool keeps spares organized. Full cord and cleating notes in Rigging That Works.