Wheeljack's unnamed invention

One of Wheeljack's unnamed inventions, this hunk of technology was presumably meant to do something at some point, but Wheeljack never really got it working. Maybe it's an ultimate weapon for defeating the Autobots, maybe it's a powerful engine, or maybe it's an energon beer fridge; we may never know for sure what its intended purpose was.

The Transformers cartoon
Unable to get the doohickey to work, Wheeljack left it in his workshop when he and the other Autobots departed Cybertron. There it sat for the next four million years until Dirge broke in and nabbed it. Returning to Earth, Dirge crashed into a swamp on a movie set, water-logging the device. Ramjet and Thrust came to his assistance, retrieving the machine and taking it back to Decepticon HQ. Megatron, sure it was some sort of deadly weapon, ordered it a demonstration, but when Thrust switched it on, it merely sparked and emitted smoke. The Decepticons presumably spent the next few months attempting to dry it out and repair it.

Kre-O online comic
Wheeljack also built the same device, along with a Wheeljack Instant Immobilizer.