Utility Outlet Box Extension Rings: Type - Utility Outlet Box; Material - Steel; Number of Gangs - 1; Height in inch - 4; Width in inch - 2-1/4; Depth in inch - 1-1/2; Capacity - cu-in - 13.0; Knockouts/Sides-Ends-Bottom - (6)1/2"-(2)1/2"-(2)1/2"; Mounting Hardware - Lugs, 4 on Corners