The , an earliest Gibson-designed vibrato systems, was a distinctive long tailpiece released in 1962 on some SG models. This mechanism later became known as the ' (or ') because of the position of the lever, which emerged from the side of the long tailpiece. This lever had only restricted movement up and down in a plane close to that of the strings, so its action was unlike that of the Bigsby and Fender units, and remains unique. It was also described as the """" in Gibson documents, but this name can be applied to any of the Gibson vibrato mechanisms. It was not a success and is of interest mainly to historians and collectors.