Boxes and Extension Ring, Octagon, Appleton, 3-1/4" with Nonmetallic Sheathed Cable Clamps, 1-1/2" deep, two nail holes each end, Volume: 11.9 Cubic Inch, Type Clamp: CL-26, Sides Knockout: 2@1/2", Bottom Knockout: 1@1/2", UL Standard: 514A, 514B, UL Lis