Belt attaching you to some object as a restraint in order to prevent you from getting hurt(noun)
WordNet. Princeton University. 2010.
Use "safety harness" in a sentence
"He found the release and pulled it, staying where he was for the couple of seconds it took the safety harness to remold itself and retract smoothly into the seat again."
"He half-turned and grabbed his trailing safety harness and held on tight with his left hand."