My fiancé and his groomsmen are pretty big, broad and stout. I believe their sizing goes up to 20", the largest neck in our crew was 19.5" and we actually still had a bit of wiggle room, not too snug or uncomfortable. The colors were perfect and look so good in person, and pair well with our dusty rose bridesmaid dresses (if you're also doing blue and pink) Very sturdy and well made