Im 150 lbs and a single tether mounted on the top of a door could hold my body weight without tearing. The rings on the end could hold half that before they start bending so I did not test it past that because i would rather not replace them after i just got the thing. The rings are the weakest link but you could easily get 4 master locks to replace the rings with something unbreakable. The rings are still pretty good though. Also when attached under the mattress when you tug on it it lifts the mattress so that distributes the force. I doubt if used correctly anyone could break the tether or escape without pulling the Velcro. less