Polarizer

A vital component of the Wheeljack Instant Immobilizer, the polarizer is attached to the dish on the top of the device. Presumably it polarizes the Immobilizer beam in some way. They're simple enough technology that they are readily available on Earth.

The Transformers cartoon
When Ironhide mistook a hologram of Laserbeak for an actual Decepticon invasion, he opened fire, and the polarizer on Wheeljack's latest invention was damaged beyond repair. Wheeljack sent Bumblebee and Spike into town to pick up a new one. The pair did so, though they got side tracked on the way back, playing video games at Robots Video Arcade and being attacked by Ravage. Hours after they left, they got back to an impatient Wheeljack, who attached the new polarizer to his Immobilizer. Unfortunately during Ravage's attack, the cat had attached a micro-bug to Bumblebee, and the Decepticons learned about the new invention and sought to turn it against the Autobots. The polarizer, along with the rest of the Immobilizer, were later destroyed by Ironhide when they did just that.