The “Killer B "ST" Is designed for any detectorist wanting true stereo sound, like many Nautilus users do. The Killer B ST's have the new style lightweight cups with an external strain relief on the coiled cord. The ST has dual 41 position volume controls, 150 ohm speaker elements, soft touch volume control knobs, a custom made coiled cord that was designed specificly for metal detectors, a mode switch that can be switched from mono to "TRUE" stereo. The Killer B "ST's" come in black and cary or famous limited lifetime warranty on the electronics. They also come with a satisfqaction money back garantee. Yes that correct, if you dont like them, pack them back up and ship them back, we will gladly refund your money.