What Is It? game 207

It's once again time for our collaboration with the always interesting What Is It? Blog. Can you guess what the pictured item is? Or can you make up something amusing?

Place your guess in the comment section below. One guess per comment, please, though you can enter as many guesses as you'd like in separate comments. 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 win 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?

For another picture from a different angle, check out the What Is It? Blog. Good luck!

Update: the object in question is a Holmes Steering Gear Clamp for towing automobiles (an antique). Aaron Rosen was the first commenter who knew what it was for, but he did not select a shirt. TDM had the funniest answer: A clothespin for chain-mail! For that, TDM wins a t-shirt from the NeatoShop. You'll find the answers to all this week's mystery items posted at the What Is It? blog.