These are the standard-sized boxes used for mounting single electrical devices such as light switches or outlets in US homes. Their approximate dimensions are 4 inches tall by 2 inches wide, with depths commonly ranging from 1-1/2″ to 3-1/2″. Whether you are installing outlets, switches, lighting fixtures, or junction connections, box size directly affects wire fill capacity, device fit, and installation quality. This guide explains typical wall-mount and floor-standing dimensions, how to read catalog sizes, and how to choose the right enclosure size for your layout. Steel City electrical boxes and accessories deliver simplicity and ease of use with a comprehensive industry-leading produ r contractors and their ever-changing needs. Learn how to. Within electrical installations regulated by NEC and UL standards, the terminology surrounding junction boxes extends well beyond simple measurements of length and width. Choosing the proper enclosure requires fluency in the language of gangs, physical footprint, and—most importantly— internal. Delete any information and specifier notes below in Parts 1, 2 or 3 which are not required or relevant for the project. Section numbers are from MasterFormat 20 20 Edition SECTION 26 05 33. 16 BOXES AND COVERS FOR ELECTRICAL SYSTEMS GENERAL SCOPE This section includes Pre-fabricated metallic.