A henley shirt is a collarless men's casualwear pullover shirt, characterize by a 10 cm to 15 cm (4-6") long placket beneath the round neckline, usually having 2-5 buttons. It essentially resembles a collarless polo shirt. The sleeves may be either short or long sleeve, and it can be made in almost any fabric, although cotton, and cotton-polyester blends, and thermals are by far the most popular. Henley shirts are generally regarded as menswear.