The box is where you're supposed to keep your shear pins. However, I wouldn't use it because the lid will sometimes open unexpectedly. Not only that, chances are that you'll need to punch out the piece of the broken pin. The tools you'll need for that, won't fit in that box. So, you might as well keep the pins near the tools you'll need to replace them.
Sounds like a perfect place to put spare shear pins.
Under 3 inches of snow.