Discover the most comfortable and supportive boys underwear with Reebok Boys Underwear Performance Boxer Briefs. Designed to keep you cool with moisture wicking and durable stretch fabric to provide a full range of motion. Reebok Boy’s Boxer Briefs have a contour pouch for added support during a workout. This five pack of Reebok boys underwear boxer briefs is made of a breathable fabric to avoid skin irritation and to maintain your kids athletic performance.. Shipping is usually free to Walmart+ members or on orders over $35.