Surface-Mounted Ballast Boxes from Vista Architectural Lighting feature heavy-walled die-cast aluminum construction for added durability. Hub openings are available on four vertical box sides in ½" NPT or ¾" NPT. 4-0 box knockouts are molded into the back of the housing to accommodate surface mounting over recessed boxes or conduit stub outs. Lid options include center hub or offset hub openings in ½" NPT. Additionally, knockouts are provided to mount the box to the wall, independent of recessed 4-0 or 4-S box tabs.