Search for the of your device (e.g., "StarTech PWDN4210D" or "Ableconn PWDN-4210D"). Navigate to their Support > Downloads section.
Probable Linux driver. ath9k_htc (in backports, open firmware) This device may be identical to the TP-LINK TL-WN722N. WikiDevi.Wi-Cat.RU High-gain Pw-dn4210d Driver Download - Facebook pwdn4210d driver full