Square D™-brand I-Line™ circuit breaker power distribution panelboards are for use on AC or DC systems. Service entrance panelboards meeting the requirements of CSA are available in Canada factory-assembled only. I-Line circuit breaker panelboards are available as 400–1200A main lugs only and 100–1200A main circuit breakers. This Square D 1200A I-Line Solid Neutral is an electrical accessory for a HCR- U distribution board. This product has UL & CSA certifications. CT suffix denotes that the neutral also includes current transformer for 3 phase 4 wire systems.