These are the rubber tarp straps that have the “S” hook on each end are used by everyone  for everything including holding tarps in place. They are called rubber bungie straps, rubber straps, tarp straps, hold down straps, tie down straps, etc. These are  made of virgin rubber, with cad plated hooks to prevent (or at least slow down) RUST. They are weather and wear resistant, and provided you do not overstretch them they will not snap.