Raising any type of poultry, pheasant, waterfowl, rabbits, quail, chukars, etc.
These cups are also useful to keep Granite Grit or Oyster Shell Calcium in for your birds
Hang a piece of welded wire in your building or garage and use these to cups to keep nails, nuts, screws & bolts in. You probably already have a piece of fencing or welded wire laying around. The shift lock design keeps them from being accidentally knocked off, & these work better & are more secure than anything that I know of that goes on a pegboard.