This is a Nyko Air Flow controller. I had one for the original Xbox. It was supposed to keep you from sweating during long sessions of gameplay, because it was ventilated and had a fan on the back. To be honest, I don’t remember it being excellent at keeping you cool. I think the fan was pretty lousy, but it was a great gimmick none the less.
I had a lot of weird controllers back then. Some good, some bad. Most of them Mad Catz.
I remember it being one of my favored chosen out of the plethora of random third party devices I had laying around. This was a step above Mad Catz for sure, but definitely still below the original controllers.