Square D-brand I-Line circuit breaker power distribution panelboards are for use on AC or DC systems. The panels, labeled cULus (compliance to UL and CSA standards certified by UL) are also Underwriters Laboratories (UL) Listed under File E33139. Service entrance panelboards meeting the requirements of CSA are available in Canada factory-assembled only. I-Line circuit breaker panelboards are available as 4001200A main lugs only and 1001200A main circuit breakers. This I-Line Panelboard is 4.5 in (H), blank extension, has a quantity of 5 ea per box.