We were one of the first homes built in our community and there was a lot of air conditioner theft back then, so I built a cage over ours. The cage was locked with two padlocks on each side. About 3 years ago I switched the locks to Master Lock Magnum disc locks because they had to be weatherproof. After the first year, these locks would no longer turn with a key. I've tried all the lubes and sprays and these things don't budge. About a month ago I saw Disk Buster on YouTube and decided to give it a try. I finally got around to trying it today and I'm pissed that I waited so long. I used a cordless drill with a 3/16" titanium bit. It glided like clockwork and in less than 5 minutes both locks were removed. This was definitely one of my best purchases.