Review on CTA USB Cable Lock – Secure Your MacBook Air/Pro with USB Type A Port – Galvanized Steel Protection with Master Key Compatibility (LT-PL) by Scott Rao

It broke as soon as I tried to use it. The label does not indicate which side is up. If you get it wrong, it will come out easily. The key mechanism turns. A complete waste of money, time and effort. UPDATE: There is a flower icon showing which side is up. When I first got it and picked it up, it didn't work. Now that you've recovered from that madness, it seems to be working. Still I don't trust. If you put it the wrong way around it will come out and I'm afraid it will be annoying again. I still wouldn't recommend it. My computer is almost 5 years old, so everything is fine. If your computer has value, invest a little more or don't waste time locking it up. You should carry it with you, because locks don't stop robbers, they only deter them.