A few months ago, I had a large plastic one fall apart on me. I was getting out of a car. I don't think it snagged on anything, but I don't know what happened exactly. I heard a snap. I looked down and noticed that the gate on the S-biner was missing. Fortunately, I didn't drop my keys or anything, but I have not trusted an S-biner since and have retired the others that I have.