The Channel Master CM 1805 Super Mast is a 5′ 18 Gauge high quality galvanized steel mast that works with all Channel Master antennas and mast mounts. Great for attic, rooftop, chimney, and wall installations. 5′ length 1.25” outer diameter 18 gauge galvanized steel For attic, rooftop, chimney, and wall installations SKU: CM-1805 Category: Accessories