Octogon Box, Size: 4", 2-1/8 Deep, Steel, Side Knockouts: 2@1/2", Bottom Knockouts, 1@1/2", End Knockouts: 4@ 21/32", Nonmetallic Sheathed CL 26 Cable Clamps, Capacity: 21.5 Cubic Inches, JB Bracket set back 1", Gauging notches set back 1-3/8" and 1-1/2"'