Repetitive stress injuries, such as carpal tunnel or flexor tendonitis, can disable workers. As a RN, 12 hours of opening individually packaged pills caused my flexor tendonitis. I finally figured out that a steel nail file could open that packaging without twisting or prying. That file is pointed but not sharp. It easily tears into the packs without being a sharps hazard. It's as washable as my hands. It is even faster than the old way.
It should be equally useful in other jobs requiring opening mail, cardboard boxes, etc. You can also take it places you can't take a pocket knife. If I had been a little brighter, I could have figured this out before I got flexor tendonitis injuries. Protect your livelihood. Your ability to work is your most valuable asset. If your job requires frequent and repetitive motions, think it through!