BUD Industries NBX-10990 Steel Internal Panel, 17-19/32" Length x 13-3/32" Width x 3/64" Thick, for NEMA Box Used to mount customer equipment inside enclosures Fits enclosure: NBB-10253,10273, NBE-10553,10573 Assembles to mounting bosses on inside of enclosure 16-Gauge galvanized steel Measures 17-19/32" length by 13-3/32" width by 3/64" thick