The ergonomic fit of the 507 is a blend of the classic 504 cap and the fit of a baseball. Made from a seamless knitted blocked wool fabric. The Seamless model Wool 507 features the original 507 cap without the stitched side panels. This cap is the perfect shape that is both a casual and stylish accessory for all occasions and activities. Crafted using a seamless knitted blocked wool fabric; Wool provides a natural source of warmth in cold winter months, providing ultimate absorbency due to its natural fibers and provides breathability by wicking away moisture from the head. Size: XL