Who remembers using these?

Who remembers using these?

Who remembers using the thing in the picture above?

If you don't know what it is, be thankful you are young... and ask someone older.

BONUS: Can you tell us why there is a square hole in the lower right corner?

For what it's worth, I remember using these (below) ...

Who remembers using these?
Who remembers using these?
Post Opinion