Middle Atlantic SPN-44-423 The Middle Atlantic SPN Universal Side Panels SPN-44-423 fit all Middle Atlantic WRK, MRK, VMRK and VRK, Series enclosures. These side panels feature stylish beveled corners to match the aesthetics of the enclosure. They easily lift off and include an internal locking kit. These panels feature a black, textured, powder-coat finish and are sold in pairs. This model is designed for use with 44U, 42 inches and 43 inches deep cabinets.