NF Panelboards provide a broad range of solutions available from distributor stock to address electrical contractor's need. NF Panelboards have modular construction to accept field installable accessories and conversion kits. This panelboard accessory is an installation kit used for main circuit breakers This kit is rated at 250 A and is for JJL, JGL, JLL and JD circuit breakers. Kit is UL listed and CSA certified.