Genuine Unistrut P1000 1-5/8" 12 Gauge Steel Strut Channel, Solid Back, Pre-Galvanized Zinc 5 Foot Length Genuine UNISTRUT Brand 1-5/8" x 1-5/8" Square 12 Gage Steel Strut Channel Solid Back (No Perforations) Channel Silver Finish: Pre-Galvanized Zinc; ASTM A653