Tears of the Kingdom
"A Zonai device that blasts out freezing air, handy for slowing and defeating some monsters. Also, some materials change their properties when exposed to very cold air."
Frost Emitter is a type of Zonai Device, which freezes enemies in the path of the cold blast it releases. While active, it drains Link's Energy Cell or attached battery, and will flash green and disappear after extensive use.
They can be found in Zonai Capsules from Device Dispensers or Treasure Chests; or lying around in the overworld. If removed from a capsule, they cannot be returned to it, although they can be fused to weapons or shields.