The Rebel Petz training leashes are made from a double braided rope with polypropylene and nylon. The inside of the rope is made from braided polypropylene, which means that the lead will float on water. The outside is made from braided nylon, which makes the lead very strong and durable. The braided material is similar to the ropes used by mountaineers, so it does not slip through the hands. The Rebel Petz training leashes therefore combine optimum strength with comfortable use.