Boxes, Octagon, Appleton, Type: 4" with armored cable clamps, 1-1/2" deep, two nail holes each end, Volume: 15.5 Cubic Inch, Type clamp: CL-25, Sides Knockout: 2@1/2", Bottom Knockout: 1@1/2", UL Standard: 514A, 514B, UL Listed: E2527, NEMA: FB-1, OS-1