Plasma thermal accelerator module

A plasma thermal accelerator module can be used as a plasma cannon if you're so inclined.

Fiction

2015 Robots in Disguise cartoon

A plasma thermal accelerator module was obtained by Windblade at some point and stored in a cache on the Moon. There it remained until Windblade warned Bumblebee and his team about it. Their mission to retrieve it was interrupted by the Stunticons, who detected it and managed to extract it from the cache by forming Menasor. Menasor installed the module in his right arm and used it to unleash a blast of energy from his eyes that sent the Autobots flying. During a later battle, the combined Autobots managed to pierce Menasor's arm with their sword and impale the module, destroying it. Moon Breaker