Magnetic inducer

Or maybe it's a laser. Lasers are the same as shells, right?

Among many things, Wheeljack's shoulder-mounted cannon can fire magnetic inducer shells. On detonation, they cover the target in a special magnetic dust. The victim, now magnetized, will find every metal object within 4000 feet is suddenly flying towards them. The dust may also force the victim to change mode and/or disable them.

Fiction

The Transformers cartoon

Following the construction of the Dinobots, the Autobots found themselves under attack by their own creations. Grimlock, Slag and Sludge rampaged through Headquarters until Optimus Prime ordered they be destroyed. Wheeljack instead suggested the use of his magnetic inducer, which covered the three Dinobots in shimmering yellow dust and forced them to return to robot mode, successfully halting their ruckus. S.O.S. Dinobots

Unite Warriors

The combiner Sky Reign could fire magnetic inducer shells from his Wheeljack arm, using them in battle with Grand Galvatron. Sky Reign Chapter

Games

Transformers Legends

When the remaining three Dinobots went on a rampage following the disappearance of Grimlock and Swoop, Wheeljack used his magnetic inducer on Slug, though it turned out to be not as effective as expected. Day of the Dinobots - Part 1