The Sentry safes are among the most common safes I know of. This is what happens when you give a society a product that is often overlooked. You can pick these safes up at any WalMart or Target for very cheap.
Yes, these are firesafes, but many many people use them to store real valuable stuff other than papers.
Here’s a few methods on how to open them.
Using a Screwdriver and penny:
Using a paperclip:
Using a homemade pick:
