These dual gears allow the use of a single motor with various pitch lens gears. Generally an issue with Panavision lenses. The iris gear has both 64 and 32 (0.8) pitches. This gear piggybacks on existing stock gear. The zoom gear has 48 and 32 (0.8) pitches. This takes the place of the existing stock gear. These work with Preston DM1(x) and DM2 (x) motors. Colors combinations will be random so gears may look different than shown. Please contact me if you would like another gear setup or for other types of motors.