With the proliferation of computers, refrigerators, and other noise-generating devices in proximity to audio and home theater equipment, a mains block entirely shielded from electrical fields takes on critical importance: hum and noise, besides distracting from sonic clarity, rob your system of crisp transient response.And unlike the overwhelming majority of mains blocks, the Supra MD06-US/SP protects against catastrophic surges from proximate lightning.Supra Cables products are best sellers throughout Europe; they provide audiophile/videophile performance at a price the average person can afford. Check the reviews at www.jenving.se!