NF Panelboard interiors can be used for applications such as commercial buildings, industrial buildings, stadiums, and offices. These interiors provide protection for commercial and industrial applications. NF Panelboards are versatile panelboards that feature a wide selection of circuit breakers, accessories, and ready to install kits. NF Panelboards have modular construction to accept field installable accessories and conversion kits. This trim and rail extension kit contains the parts required to provide a 12 inch extension.