Gibson 490R and 498T Gold Humbucker Pickup Set Gibson IM90R-GH 490R Gold Humbucker and Gibson IM98T-GH 498T Gold Humbucker The special Alnico II magnet gives these beauties a singing quality that delivers on demand. Put a slightly hotter Alnico V magnet into a specially wound coil combination, and you get the 498T "Hot Alnico"