Fotga DP500III Mark III Quick Release Dampen Follow Focus A/B Hard Stop with Swing Rocker Arm for 15mm and 19mm Rods System for Blackmagic BMCC BMPCC 5DIII 5DIV A7R A7S GH3 GH4 D500 Newly design on its inner structure to reach a high level in this field, while the damping gives virtually zero backlash(&lt;0.5mm) Long-life precision engineered gearbox enables accurate and reliable focusing Material: Sturdy Metal CNC Machined,2 levels adjustable damping Integrated with A/B Hard Stops, stoppors can also be detached and then stored in the slots within the follow focus itself Drive gear can be mounted from both side.(Works for both right-handed and left handed) Sony A7 Series,A7,A7R,A7S), A7II SeriesA7II,A7RII,A7SII, Panassonic GH3/GH4, Blackmagic BMPCC, Canon5DII/5DIII/5DIV, Nikon D500 Blackmagic BMPC/URSA/URSA mini, Sony FS100/FS700/FS5/FS7/F55/F5/F3, RED SCARLET/EPIC/RAVEN/ONE,Kinefinity KineRAW/KineMAXetc. Net weight: 340g