What Is It? is a place for engineers to test their knowledge (and sense of humor). Each week the CR4 team will post an unidentified picture. We're looking for your best (or funniest) guesses at what it might be (or could be) in the comments below.
Got an image* that you think would stump the community? Submit the photo to the blog admins and we'll post it!
*No vulgar or obscene photo submissions, please.