These are great shirts. I wear mediums for my street clothes, but the larges for work. Soft, breathable, and durable. They seem to wick sweat well and keep odors to a minimum. I'm 5'9" 155lbs and the mediums are perfect. I on to wear the larges at work because they stay tucked in and my tool suspenders stretch the neck on mediums really bad. The only reason these aren't 5 star; the tags. Itchy, long, and not easy to tear away. They need to print their tags.