5XL- Under Armour Men's Performance Mesh Tech Underwear - Pack of 2 The "5XL- Under Armour Men's Performance Mesh Tech Underwear - Pack of 2" is a set of two black boxer briefs designed by the brand Under Armour for men. Made from polyester microfiber material, they feature a solid color with the Under Armour logo as part of the theme. These boxer briefs are in size L and are constructed with stretch and breathable fabric, suitable for all seasons. Ideal for active wear, they offer comfort and performance with the mesh tech design.