Extra-tough nylon strap works just like a big rubber band. Works on the principle that a lighter object (your vehicle) can move a much heavier object (a truck or 4WD) when used with forward momentum. Strap stretches out and then "snatches" the stuck vehicle out of snow or mud…no damage to the drive train of the towed or towing vehicle. Rot and mildew resistant—won’t absorb mud or water.