I, Robot Wiki

The NS-5 (Nestor class 5) was the name of the USR's current android model. Sonny is a modified NS-5.

The NS-5's were a marked technological improvement over their predecessors the NS-4's which lacked the NS-5's strength, speed and flexible faces.

Viki hardwired the NS-5’s to carry out a assault to the Lake Michigan Facility and the storage containers to destroy the NS-4’s. Upon doing so Detective Spooner watched in horror and decided to run, the androids almost caught the detective, but the NS-4’s leaped into action, saving him and buying him some time. But when they tried to fight back and said “Human in Danger” they ultimately got dismantled .

The NS-5’s were sent out to attack the People in Chicago sparking a war, and attacked a police department, injuring some officers. In the end the NS-5’s were recalled by USR. To mostly be storage away for good, but then the robots noticed the collapsed bridge imaging Sunny’s dream in real life.