Passive pickup for four string bass guitars with Alnico 5 magnet. Hum-canceling Stack for Jazz Bass with increased output and fatter tone for any 4-string Fender American Standard Jazz Bass. We took the noiseless Classic Stack and ratcheted up the tone another notch. For this pickup we increased the output and thickened up the mid-range response, which gives rock tones an added push without getting harsh. This hum-canceling pickup is designed as a drop-in replacement for Fender American Standard Jazz Bass neck position pickups. - Number of Conductors: 4 - DC resistance: 25 kOhm - Colour: Black.