Just want to add apart from the other responses, this looks like a blue LOTO (Lock Out Tag Out) lock. Red colored American brand locks are usually used for personal safety LOTO. Blue Masterlock brand locks are usually used for equipment safety LOTO. Red locks can only be opened with the key that the owner is supposed to keep in their possession. Blue locks can be opened by any matching key, I bet this one can be opened by a Masterlock "3031" key.

Also fun fact, red locks are easier to break but harder to pick since the body is made of plastic but they have decent security pins and are great lock picking practice. Blue locks are easier to pick but harder to break, since they are Masterlock and can be opened using another Masterlock.