Cryogenic sprayer
From Transformers Wiki
A cryogenic sprayer is a Transformer surgical tool. It freezes things, presumably through the application of liquid nitrogen.
Fiction
Marvel Comics continuity
Ratchet was fitted with a cryogenic sprayer. He used it along his laser scalpel against Megatron, but couldn't so much as get a scratch in his armor. Warrior School!
About a year later, Ratchet was forced to act as a getaway car for two car thieves in order to keep his identity as a Transformer secret. To get rid of the cops following them, Ratchet used his cryogenic sprayer on the road behind him, taking out two of the three police cars. Seeing as how one was busy driving and the other paralyzed with fear, Ratchet hoped the thieves didn't notice his aid. They did though, and the one named the Mechanic removed the cryogenic sprayer along the laser scalpel from Ratchet's interior.
To keep his cover, Ratchet did nothing until the thieves reached their garage, at which point he transformed and demanded his surgical instruments back. The Mechanic gave him a full dose of his cryogenic spray, then left the garage with his accomplice to follow the robot to his undoubtedly weapon-filled lair when he'd defrost. Funeral for a Friend!
Having gotten away with not only Ratchet's cryogenic sprayer and laser scalpel but also the power booster rod, the Mechanic had become a prime target for the Autobots. Using those tools to pull one amazing heist after another, the Mechanic also had become a prime target for the Portland Police Department. After picking up a signal from the power booster rod, Blaster and Goldbug were sent out to retrieve the weapons, but just before they could take them back, the police showed up and opened fire on them. The Mechanic and his accomplice made use of this by getting in the car, driving away and freezing the road behind them.
Despite that the police and Autobots decided to work together and managed to arrest the Mechanic's criminal circle, he himself got away with the tools. Mechanical Difficulties! The cryogenic sprayer was never seen again, but presumably the Mechanic, if he was never apprehended, kept it.