The Lululemon Masons Peak Flannel is a versatile button-down shirt designed for men in size M. Made from 100% polyester, this black and gray plaid shirt features a collared neck and long sleeves, making it suitable for various occasions such as travel, casual outings, or business meetings. With a regular fit and machine washable fabric, this button-up shirt from the brand Lululemon is ideal for any season, making it a stylish and practical addition to any man's wardrobe.