What Is It? game 318

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 the other mystery items, too, at the What Is It? Blog. Good luck!

Update: This is a lawn mower blade balancer.It is used after sharpening the blade to ensure that each half of it weighs the same. You can see a video of the process at the What Is It? blog. We, of course, were looking for imaginative but wrong answers. Tapisbis had a good one,

It's one of the first artificial Christmas trees. Before plastics became common, scientists searched for viable artificial Christmas trees, this early tin example was quite popular although balancing the ornaments on the shelves proved challenging after a couple of eggnogs.

Which is deserving of a t-shirt from the NeatoShop! Another one goes to Warren Auld, who said it was “Archimedes drain plug. Also the reason he suddenly shouted ‘Eureka!’” Ha! Thanks to everyone who played this week, and thanks to the What Is It? blog.