Now it's time for our collaboration with the awesome What Is It? Blog! What is this thing? You don't have to know to win!

Place your guess in the comment section below. One guess per comment, please, though you can enter as many as you'd like. You might know the true answer, but we're going to select two winners who come up with the funniest, most outlandish guesses to win a T-shirt from the NeatoShop. However...

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?

Check out more pictures of this thing at the What Is It? Blog. Good luck!

Update: this turned out to be a Type K D.C. Relay that was made by the General Railway Signal Company. We had a lot of funnier guesses. Trillian guessed it was an emergency jumpstarter for Frankenstein's monster. That's good for a t-shirt from the NeatoShop! Another great guess came from azog, who said it was "an early prototype of a defibrillator. Unfortunately it tended to blow off the patients thumbs." That paints a picture, alright, and it's good for a t-shirt as well! Find out the identifications of all the mystery items of the week at the What Is It? blog.