Stay fashionable and warm this winter in the Burton Birdie Beanie. Chunky knit exterior in a classic-looking style gets a comfy upgrade with a soft interior lycra lining. The long pile fibers lining the Birdie Beanie feel as soft as a fur rug, making itchy foreheads a thing of the past. Brimless skully fit is designed to hug the skull and keep warm air from escaping.100% Acrylic. Soft Lycra® Pile Lining. Skully Fit. Burton's W48 Warranty Program.