Under Armour Boxerjock Performance Tech Mens Size 37-41 XL 3 Pack Boxer Briefs The Under Armour Boxerjock Performance Tech Men's Size XL 3 Pack Boxer Briefs in black are designed for high-performance comfort and support. Made from polyester material, these boxer briefs are machine washable for easy care. With a solid color pattern and a sporty theme, these boxer briefs are perfect for active men looking for durable and stylish underwear. The 3-piece pack ensures you have an ample supply of underwear for an extended period of time, making them a great addition to your wardrobe.