They are quite small and easily recognizable due to the red police light atop their bodies. GO-4 is equipped with two salute-ready arms and an anti-gravity stasis beam (similar to that of Stewards). For communication, they had various beeps and other sounds and a cat-like hiss for rage. GO-4 units also can deliver coffee to superiors (although never seen in-film).
One GO-4 unit served aboard the Axiom as the Captain B. McCrea's first mate and helped Auto in his attempt to carry out Directive A-113. He was accidentally destroyed when he attempted to assist AUTO in taking down Captain B. McCrea and was kicked and sent flying through a window and crashing down near one of the swimming pools in the Lido Deck.
GO-4 used his personal elevator system to move fast around the Axiom. The entrances/exits of the elevator were usually at Steward Kiosks; the places where SECUR-T (Stewards) would wait inactive until they were needed. The elevator also granted GO-4 an access to the captain's quarters.
- GO-4 appears briefly in the short movie BURN-E.
- GO-4 also appeared in the video game, but He does not get destroyed.
- The name GO-4 is a pun on how personal assistants are often referred to as "gophers" - a verbal pun as they are often sent to "go for" things.
- When GO-4 is sent flying out of the window, he makes a whistling sound and a smash sound very similar to the sound Wile E. Coyote makes when falling off a cliff in the Warner Bros. cartoon series Looney Tunes.