Static shield

A static shield, or low-frequency shield, was a security device Spock rigged to the USS Enterprise's navigation console in 2269. It protected an area of three square meters.

That year, a magnetic organism ordered Captain James T. Kirk to remove the shield from the navigation console. Kirk refused, ordering it to restore life support systems first. The organism then activated the automatic bridge defense system, shooting Kirk and Spock, before reiterating its request. (TAS: "Beyond the Farthest Star")