The best one is call aura hd wireless dongle and you can find one on eBay for about 8 to $12 U.S.
But if you want 7db antenna is on sale for $5 on eBay the seller name is westernpowers but I don't
Know if this antenna work on mag 254 from my knowledge the aura hd work best.
looking for wifi antenna that can reach long distance, because in most hotels the farther your room is from the front desk where router is located the worse the strength is, please let me know best distance option