This is a penny date sorting kit, an example of one way to sort coins that you are searching for errors. You put all of the coins that you find for a particular date (which has an error associated with it) into the box with that date label and then you go back later with your higher power magnifier and look for the error associated with that date. I know it sounds confusing but it gets more understandable and easier with just a little practice. The one point that it is difficult for beginners to really understand is that errors are not random - each date has a particular error or multiple errors associated with it because the die - the thing that stamped the coins actually had the defect and usually stamped out thousands of coins before it was noticed. These errors are catalogued and well documented.