Furutech NCF Clear Line sold individually Line-XLR(F) Optimizer,

---------------------------------------------------------------------- Simply plug the NCF Clear Line-XLR(F) into an available output jack on your device, or the NCF Clear Line-XLR(M) into an available input jack. For best results, plug this product into an available output or input jack on your system's preamp or SACD/CD/multi-player. Increased clarity and reduced high-frequency noise. Increased overall contrast and reduced muddiness and looseness.