tri-mountain 860 mens rayon/poly long sleeve shirt with mini-houndstooth pattern - ivory - 5xlt tri-mountain a beautiful 5 oz. wrinkle-resistant blend of 50% rayon/ 50% polyester microfibers in a time tested classic mini houndstooth design. the perfect shirt to wear for all day performance. this men's long sleeve shirt also features a button-down collar, left chest pocket, two-button cuff and central pleated yoke back with loop, s-6xlt.