W-Valley is made of 28 or 26 Gauge Steel, Options availble: Closed Hem, Open Hem, No Hem, and 1-Rib, 2-Rib, 3-Rib and 5-Rib 10' long. W-Valley Flashing protects the critical area of the roof where two slopes come together to form a valley. W-Valley Flashing will channel runoff water down the roof and into the gutter. For architectural, residential, and commercial roofing. ASTM A-653, ASTM A-792