Unistrut P2072ASQ EG Post Base, 6 IN Length, 6 IN Width, 3-3/4 IN Thickness, Number Of Holes: 6, Hole Size: 9/16 IN, ASTM A575, A576, A635 Or A36, ASTM A1011 SS GR 33 Steel, Electro-Galvanized Conforming To ASTM B633 Type III SC1, For Use With 1-5/8 IN Channel