3 treble and 3 bass, set of 6. Distinctive in styling and quality, the Imperial? made it?s first appearance in the 1970?s. The most notable feature of this unique machine head is the futuristic Three Step button, a fresh and funky design trademarked by Grover. This re-introduction if the Imperial? is an exact reproduction of the originals, including a 16 to 1 gear ratio.