The MB-26 from Arri is a 4×4 production matte box, with a four rotatable stages back to accomodate for four 4×4 filters, and one 4 1/2 round filter. It slides onto 19mm rods in the studio configuration. One of the filter frames is toothed for operation by turning knob or flexible shaft. At the rear of the filter stage there is a receptacle for 4 1/2″ filter rings and for an anti-reflection ring. For easy lens changing the matte box swings open 90°.