Introducing “Build Your Own Jet Engine,” an assembly kit perfect for that aviation geek in your life. This 3D printed model fits comfortably on desks, mantelpieces, and most birthday cakes. Today, July 11, 2014, you can enter to win one at artsandaircraft.com. The fine print says that you must be 18 or over and a resident of the U.S. for us to send you one. Additionally, Tumblr didn’t endorse, administer, sponsor or additively manufacture these engines, and only the GE social media team will receive participant information.