SQUARE BOX EXTENSION RING TYPE; STEEL MATERIAL; 4 INCH; 4 WIDTH IN INCH; 4 INCH; 4 HEIGHT IN INCH; 1-1/2 INCH; 1.5 DEPTH IN INCH; UL 514-A, UL 514-B, FS W-J-800E APPROVAL; 50 STANDARD PACKAGE; 21 CU INCH CAPACITY; (12) 1/2 INCH SIDES KNOCKOUT SIZE