I got a flyer for $40 Laptop Locks in mail from mac

how secure is it?

any other alternatives?

I want to have my laptop on my desk all the time without worrying of theft.

I also need it on move in day, don't wanna carry around my laptop during welcome week.

I bought one and put it on my laptop and all,
yeah I don't wanna take the chance of someone stealing it or whatever lol

The lock is definitely a good idea to have for the laptop. I would keep it locked at all times, even in your residence, just incase some maintenance people come in to check stuff (if light bulb is out or heater isn't on, etc)