This is a flour sifter. Do you have one? Do you use it? I use mine all the time. Sometimes when I am getting flour out to use, it looks a little lumpy. Putting the flour through the sifter aerates the flour and gets any lumps out, making it more fluffy.
According to WhatsCookingInAmerica.net, a sifter is ...
a sieve that is especially adapted for use with flour. It is commonly built
in the form of a metal cup with a screen bottom and contains a mechanism (wires
that either revolve or rub against the screen being operated by a crank or a
lever) to force the flour through the mesh.
Oh, and you should know that there is no need to wash your sifter each time you use it. Just tap it gently over the sink or trash can and shake out any extra flour. I used to wash my first sifter after every use. What happened to it? It rusted. A sweet friend informed me that it was, after all, only flour that I used each time I sifted and there was no reason to wash it all the time.