Seymour Duncan Quarter Pound Jazz Bass Set Electric Guitar Electronics Quarter Pound Jazz Bass set with diameter alnico 5 rod magnets delivers all the attitude you could ever want from a Jazz Bass. These are drop-in neck position replacement for any American Standard Jazz Bass. Hand built in Santa Barbara, CA the Quarter Pound for Jazz Bass uses diameter alnico 5 rod magnets, forbon flatwork, and is wax potted for squeal free operation. Comes with black cover.