I wrote this agreement by taking the best ideas from all the agreements I have seen used in my area. It protects the expensive equipment from being damaged, lost or stolen by placing responsibility on the students and their parents to replace any part that is lost or damaged due to misbehavior. It is very preventative as parents will typically lecture their kids on being careful with the equipment before they sign the contract. I use it and haven't had anything lost or broken due to misbehavior