New Work Ceiling Fixture & Junction Box, Captive Nails

New Work Ceiling Box With Captive Nails, Grounding Lug & Screw Attached, 20 CUIN Capacity 3/0 - 4/0, 6 Integral Clamps, Fixture Spacing For 2-3/4" - 3-1/2", Combination 4" Diameter x 2-1/4" Depth, For Light Fixtures & Junction Boxes, Not For Use With Ceiling Fans.