The Gibson G3 bass was a companion model to the Gibson Grabber, and a bass version of the S-1. It debuted in 1975 with the same body shape and styling as the Grabber but a different (and innovative) pickup configuration. It still had a maple or alder body and maple bolt-on neck with the Flying V- like arrow headstock, but had three single-coil Bill Lawrence pickups, wired in humbucking configuration.
Sonically it was much more like a Fender than a Gibson, and was perhaps aimed at taking some of their market share. It was a popular bass with a much brighter sound than Gibson basses were usually associated with.
Similar models include the Ripper and the G3's cousin, the Gibson Grabber, which both looked similar, but had a set neck rather than a bolt-on. The Grabber had a bolt-on neck, but had one sliding pickup.
In 2012 Gibson reissued the G-3 as Gibson Grabber 3 70's tribute bass, which featured three pickups and a set neck. The pickups were specifically designed for this edition of the bass and were placed differently, being the neck pick up much closer to the neck than the original G-3.