Cryolator

The cryolator is a unique weapon in Fallout 4.

Background
A part of the Vault 111 experiment, besides using cryosleep pods, was to find other uses for cryotechnology, primarily using it as a weapon. Conceptually, it is a flamer that shoots ice.

Characteristics
The weapon creates a cryogenic spray when fired that fades away at mid-range. Firing continuously at an enemy may freeze it solid and render it unable to move or attack for a period of time. More durable enemies will require longer exposure, and some cannot be frozen at all. The Cryolator can chew up large amounts of (rather expensive) ammunition, so use it wisely.

The Crystallizing Barrel mod will convert the weapon into an automatic crystal shooter. This makes the weapon far more ammo-efficient, as well as granting additional benefits such as increased range, increased damage (crystals do physical as well as energy damage), and a very small AOE effect. However, the projectiles do not travel particularly quickly and suffer from a noticeable flight trajectory.

Locations
Inside Vault 111, in a display case in the Overseer's Room behind a Master level lock. It cannot be picked up at the beginning of the game due to the inability to pick Master level locks before exiting the Vault. Interaction with the case prompts a line from the Sole Survivor, saying that he/she will return for it later. An entry on the Overseer's Terminal in the same room can be found detailing the weapon and why it was built. Dogmeat can fetch the Cryolator for the Sole Survivor without picking the lock in earlier versions of the game, but this has now been fixed (you still get the Cryolator with the help of Dogmeat but it won't have any ammo).

Sounds
Криолятор