Here's a description from the internet:
Improve component performance simply by improving your power cord. Cardas' Golden Power Cord makes a significant upgrade to the low-quality AC cords supplied with most hi-fi and home theater components. Use it with any component that comes with a detachable IEC-type power cord, and you'll notice an immediate improvement in sound quality with audio gear and picture quality with TVs, monitors, DVD players, and VCRs.
Few other components make such a cost-effective improvement to your AV system as a Cardas power cable.
The Golden Power Cord provides a very low noise path from the wall plug to your components, eliminating internal noise generation or radiation. It also reduces component generated noise, such as the clock noise from digital components, preventing it from 'polluting' other gear on the same circuit. Golden's construction features patented Cardas Cross, 10.5 net-gauge, multi-stranded conductors insulated with pure Teflon. The conductor geometry incorporates a specially designed, silent, litz array that cancels very high frequencies for a dramatic decrease in interference. Premium connectors ensure quiet, positive electrical contact.
Free your audio and video components from constrictive, noisy power cables. Start using the Cardas Golden Power Cord instead and enjoy your performance upgrade.
Should fit in a medium USPS flat rate box:
Domestic Rate: $11.35 at the Post Office™
International Rate*: $32.95 (Mexico/Canada), $47.95 (all other countries) at the Post Office
Size: 13 5/8" x 11 7/8" x 3 3/8"