This is an item in Snowpiercer (TV Series) episode 3 Access Is Power.
Description
This is an item used by all Train employees to access the doors and other features. It is embedded into their hand in between the thumb and index finger. The chip was sold in the black market by a brakeman to John Osweiller. This chip was stolen from the hand of a deceased employee that was killed by the train's serial killer. The chip is then kept in a small capsule to be used by John Osweiller to open a door.