The MPB9 is a nine-hole Type 12 mild steel miniature pushbutton enclosure in ANSI 61 gray, part of the MPB Series. It accepts nine 22mm miniature oil tight pushbuttons, switches or pilot lights and protects them from dirt, dust, oil and water, giving room for a fuller operator station in an 8.50 in by 6.50 in footprint. The MPB9LG is the RAL7035 light gray version.

The MPB9 uses an internally hinged removable cover designed to hold the cover open during wiring. Its body is formed 16 gauge steel with smooth continuously welded seams, welded brackets provide for enclosure mounting, and captive cover screws thread into sealed wells. The cover seals on an oil resistant gasket and adhesive, and a bonding stud on the door and grounding stud on the enclosure are provided. Cover and enclosure are phosphatized and powder coated ANSI 61 gray.

Dimensions are 8.50 in (216 mm) high by 6.50 in (165 mm) wide by 4.25 in (108 mm) deep. The drawing shows 9.50 in overall height, an 8.81 x 6.81 in door, a 7.50 x 5.46 in door opening and 4.29 in inside depth. The 0.89 in pushbutton holes are on 1.88 in vertical and 1.50 in horizontal spacing, and the 0.25 in mounting holes are on 9.00 x 5.63 in spacing.

The series is rated UL 508A Type 12 and 13 and CSA Type 12 and 13, and complies with NEMA Type 12 and 13 and IEC 60529 IP54; appropriate components are required to maintain these standards. It carries UL File # E65324 and CSA Cert. # LR21001, is REACH and RoHS compliant, and ships in a box at 5.75 lb (2.61 kg).