The frame allows 138mm dioptres of up to +2 strength to be used with an ARRI LMB mattebox.

The dioptre frame is the width of two 4″ x 5.65″ filter frames and fits into a 2- or 3-filter stage mattebox. It also features a safety mechanism to prevent the dioptre from falling out of the frame during exchange, while two 1/4 inch threads permit the frame to be attached to an articulating arm.