From Halopedia, the Halo wiki
The Coldsnap Launcher is a double-barreled mounted launcher, primarily mounted on Bisons. Due to the lack of available Bison vehicles aboard UNSC Spirit of Fire, the weapon remains experimental. It fires experimental cryo shells that damage and chill enemies caught in its area—of—effect. The launcher can be upgraded, which increases the launcher's range, rate of fire, and chill effect. When the Bison deploys it leeches ambient heat energy to augment its defensive systems, creating a chill aura that affects nearby enemies. These systems can also be upgraded to further boost defenses and the area of the chill aura.
List of appearances