Credit Card Reader. -- 신용카드 리더

Does anyone have any information about credit card readers in Korea? In America I used "Square" -- but Square doesn't work with Korean cards (KB, Samsung, Hyundai, Lotte, and some BC Cards). 

Any information about a card reader that would work with these cards and internationally accepted cards (Visa, Master, AMEX, etc) please feel free to respond. 


Thanks greatly for your time in advance~