OS1st has applied their medical grade manufacturing technologies and unsurpassed quality to an increasing consumer health and protection need, travel health and safety.OS1st TS5 Travel Socks have medically correct graduated compression for the prevention of venous issues related to long term sitting, such as air travel and other forms of extended immobility. OS1st products are especially known for quality, comfort and ease of use. You will not believe you are using an FDA medical device.