I became aware of the usefulness of the "shove knife" during my years as a firefighter. My daughter began college this year; each bathroom in her dorm is shared by a pair of dorm rooms in a "Jack and Jill" configuration. Unfortunately, after using the bathroom the suite mates across from her couldn't ever remember to unlock the door to my daughter's side. Consequently, my daughter and her roommate were locked out of their own bathroom almost every morning when they needed to get ready for class. This tool solved the problem. I showed my daughter how to use it to defeat the locking mechanism on the bathroom door. She was able to learn the skill quickly, and can now easily unlock the bathroom door when she gets locked out. It is well built, works great and is well worth the money!