Xci NB is an energy efficient rigid insulation panel composed of a closed cell polyisocyanurate foam core bonded to a premium performance coated glass facer on one side and 7 /16″ or 5 /8″ OSB or plywood on the other. This product is designed for use in Type V commercial and residential wall applications providing continuous insulation and a cladding attachment substrate. Do not countersink fasteners.