The MB-14 production matte box is equipped with a 4x filter stage for four 6.6" x 6.6" push-through filters (rotatable in pairs). Two of the filter frames are toothed for operation by knob or flexible shaft. The 4x filter stage has a rear receptacle for 6", 138 mm or 40" filter rings, for anti-reflection rings and additional 4" x 4" filter stage. The 4x filter stage can be interchanged with other filter stages. For easy lens changing the matte box swings open 90° to the front. The lateral adjustment on the side of the matte box is equipped with a quick-set clamp. A holder for secure mounting of french flags is included.