WJCO
Meme King
That looks like an air powered bleeder of some sort. Brake bleeder?
Looks like some sort of fluid extractor?
Edit: boardsurfer beat me to it..haha
Nope.
Homemade vacuum leak tester. Hook one end to air and the other to a vacuum port... pushes smoke through the system to find the leak.
^ Yep, this is it. Homemade Leak Detection, uses smoke to find EVAP leaks or vacuum leaks. The JK has an EVAP leak and the wj has a leak for the rear air locker. Got this thing for 70 bucks online. It works damn good too.