The NAILOR 4320 Series features four individual stamped pattern controllers mounted on the rear of the diffuser face. They are easily field adjustable to suit the desired air pattern.  * Material: Corrosion-resistant steel. * Discharge pattern can adjust to 1, 2, 3 or 4-way horizontal, before or after installation. * Discharge pattern is adjusted by dropping the perforated face and rotating the pattern deflectors. Diffusers are shipped from the factory with a 4-way discharge pattern. * Removable face has concealed latches for easy access to core and optional damper. * Perforated face has 3/16" diameter holes on 1/4" staggered centres. * Excellent performance in VAV systems. * Standard finish is AW Appliance White.