the medium and small clip are a 5/5 in. terms of strength. the larger clip broke/snapped when I tried opening it all the way. The PETG material memory isn’t perfect and changes after use. the clips wouldn’t fully close, meaning return to their original shape after being used (opened all the way) a couple times. However, the clip memory is easy to restore. I dipped two of the clips in boiling water for approximately 5 seconds and they quickly returned to their original shape. then I ran them under cold water and they were like new again.