The Medical Device Information & Technology Assistance Center or Chamber of commerce or Association authorities have to provide this letter and have it legalized by the Royal Thai embassy in country of origin. Or you can use the official letter [Woosam Medical Co., Ltd.] and have it certified true and correct contents by The Medical Device Information & Technology Assistance Center or Chamber of commerce or Association authorities and have it legalized by Royal Thai embassy in country of origin. Please let me know your thought.