TP-Link Gigabit Powerline Networking Kit | $40 | Amazon
Graphic: Shep McAllister

Say your wireless router can’t push a strong signal to every corner of your house, or maybe you own some kind of old set top box that needs an ethernet connection, but doesn’t live near the router. A simple powerline adapter is one of your best options for extending a home network, and Amazon’s top seller is down to $40 today, a 20% discount.