NeweggFlash offers the TRENDnet AC600 Dual Band 802.11ac Wireless USB Adapter, model no. TEW-804UB, for $14.99 with free shipping. That's tied with last month's mention and the best price we could find for any 802.11ac USB adapter. (It's also a current price low by $4.) It features speeds up to 433MB/s and simultaneous 2.4GHz and 5GHz frequencies. Deal ends December 28.