 The pickup selector switch gave five single-coil options in the "up" position, and four humbucker combinations in the "down" position, plus an "off" position.The name M-III refers to the Gibson M-III model, which was a Superstrat-style guitar, for which these electronics were originally developed.The Gem Series (1996-1998) had P-90 pickups and special finishes in "gemstone" colors