Steel City 1-Gang 4 in. 2-1/8 in. D New Work Metal Utility Box 5837112-25R - The Home Depot

Steel City 1-Gang Utility Box Silver 5936112-20R - The Home Depot

Steel City 4 in. Single Gang Blank Utility Box Cover 58C1-25R - The Home Depot

Steel City 4 in. 2 1/8 in. 2 1/8 in. 14.5 cu. in. New Work Handy/Utility Metal Electrical Box 3/4 in. Knockouts 1-Gang 58371.75 - The Home Depot

Steel City 2-1/8 in. D 4-11/16 in. Red Box 72171-1234RD - The Home Depot

Steel City 1-Gang 4 in. 2-1/8 in. New Work Metal Deep Handy Box with T-Bracket 58371T12-12R - The Home Depot

Steel City 1-Gang 4 in. 2-1/8 in. D New Work Metal Utility Box 5837112-25R - The Home Depot

Steel City 1-Gang 4 in. 30.3 cu. in. Metal Square Electrical Box 521711-25R - The Home Depot

pigtail plug boxes - maybe aka suspended receptacles

Steel City 1-Gang 4 in. 2-1/8 in. D New Work Metal Utility Box 5837112-25R - The Home Depot

Steel City 1-Gang 3-1/2 in. New Work Metal Octagon Electrical Box (Case of 25) 2415112-25R - The Home Depot

pigtail plug boxes - maybe aka suspended receptacles