
Explanation: Small hole under the lock: With locks that are left outside all day and night, rainwater will often seep inside and cause rust. This hole is to drain rainwater. Not only that, this is also where you put grease.

Explanation: Small hole under the lock: With locks that are left outside all day and night, rainwater will often seep inside and cause rust. This hole is to drain rainwater. Not only that, this is also where you put grease.