Octagon Box, 15.8 Cubic Inches, 4 Inch Diameter x 1-1/2 Inches Deep, 1/2 Inch Knockouts, Pre-Galvanized Steel, Drawn Construction, with Armored Cable Clamps (C-3) and Adjustable Bar Hanger 10-1/2 Inch to 18-1/2 Inch, For use with Armored/Metal Clad Cable