Hey look! It's time for our collaboration with the wonderful What Is It? Blog! Do you know what the objects in this picture are? Guess and win a t-shirt from the NeatoShop! But first, read the rules:

Place your guess in the comment section below. One guess per comment, please, though you can enter as many as you'd like. Post no URLs or weblinks, as doing so will forfeit your entry. Two winners: the first correct guess and the funniest (albeit ultimately wrong) guess will each win a T-shirt from the NeatoShop.

Please write your T-shirt selection alongside your guess. If you don't include a selection, you forfeit the prize, okay? May we suggest the Science T-Shirt, Funny T-Shirt and Artist-Designed T-Shirts?

There is another picture of these mystery items at the What Is It? Blog. Good luck!

Update: the small objects are copper crushers or copper pressure cylinders from the Frankford Arsenal. The What Is It blog explains how they are used to measure the force of a gun's chamber pressure. The first correct answer came from theoneandonly, who wins a t-shirt! The funniest answer was "flute holes" from Lucas Gentry. That's good for a t-shirt from the NeatoShop, too! Thanks to everyone who played, and thanks to the What Is It? blog!