USB AC600Mbps Mini WiFi Adapter 802.1ac Dual Band – $7.99 Free S/H with Prime

In case you don’t want the free after rebate option that is on the FP now, this one is faster and reasonable price.
https://www.amazon.com/dp/B01M17UTSJ
Use promo code TXYPGEKW to get $5 off = $7.99 total
802.11AC – check
Dual Band – check