Proozy offers the Columbia Men's Whirlibird Watch Cap Beanie in Black for $11.99. Coupon code "DN599" cuts it to $5.99. With free shipping, that's tied with last month's mention and the lowest price we've seen. (It's the best deal now by $9, outside of the mention below.) One size fits most. Deal ends December 18.

A close price: Lyons Trading via Amazon has it for $6.99 with free shipping for Prime members.