The Powerline 1000 adapter is equipped with an extra noise filtered power socket. Why do you need it? Because you need to connect the Powerline 1000 adapter to your modem/router in a place where very often other appliances need also a power supply. Do not waste any power outlet. Plug the Powerline 1000 adapters directly into the wall outlet and use the extra noise filtered power socket to power your appliances or to plug in a power strip. The integrated noise filter reduces electrical interference and improves the performance of the Powerline communications