Fotga DP500 III Follow Focus with A/B Hard Stops and 15mm Quick Release Rod Clamp for Sony A7 A7R A7Rs II III A9 A6000 A6300 A6500 Panasonic GH3 GH4 GH5 GH5s Canon EOS 6D 7D 5D Mark II III Nikon D850 Material: Sturdy Metal CNC Machined,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,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),Drive Gear Interface: Compatible with JTZ X Type Interface Standard Can use different size gears to meet your need with different lenses. This set comes with 3 size gears.(M0.8-38T/M0.8-43T/M0.8-65T) All made of metal except the gear,detachable structure can makes it work for 15mm/19mm rail rod rig only need to change the rail rod clamp (Only included the 15mm clamp) 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,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. The outside of wheel is made of <span class="a-text-bold">rubber</span>,nice touching and keeping the movement stable. White mark ring contains <span class="a-text-bold">magnets</span> for easy installation and disassembly. Comes with <span class="a-text-bold">3</span> size gears: M0.8-38T /M0.8-43T /M0.8-65T. Drive gear can be mounted from both side.(Works for both <span class="a-text-bold">right-handed and left handed</span>). Drive Gear Interface: Compatible with <span class="a-text-bold">JTZ X</span> Type Interface Standard (JTZ DP30 Series). Connector size:<span class="a-text-bold">12mmx12mm.</span> 90 degree right angle and bulb knob design,very convenient to control the follow focus. Safty-lock design at the 12mmx12mm terminal,makes it insert the follow focus firmly,not falls off. Made by CNC machine. Material: Metal. What in the box: Fotga DP500 Mark III Quick-release dampen follow focus with A/B hard Stops x 1 0.8mm matching gear belt x 1 M0.8-38T/ M0.8-43T/ M0.8-65T gear x 1 Speed Crank Handle x 1