Features:
The follow focus finder can let you shoots precisely, focus precisely and operate smoothly in film shooting. 
This improved Follow Focus Integrated with A/B Hard Stops which have easy begin/end setups for fast repeatable racking between two points, and make focusing lenses that have no hard stops much easier.
Quick-release version, easily attach and detach.
This FOTGA DP500IIS follow focus is upgraded based on the previous DP500II version follow focus.
It is consisting of a dampened gearbox. 
There is a button downside can adjust the tension of of the gearbox to reach 2 dampen level.
Gear drive can be mounted from either side.
Scale mark part of this follow focus can be rotated, you can adjust the scale mark to the point where your sight can reach. 
Compatible with 15mm rail system.(60mm center to center difference).
Suitable for lenses diameter from 46 to 110 mm.
The special part of this follow focus is it can use different size gears. It can work with 3 different size gear to meet your different need with various lens:
M0.8-38T gear: 38T (38 teeth) 0.8mm pitch, diameter is approx.28mm (not included)
M0.8-43T gear: 43T (43 teeth) 0.8mm pitch, diameter is approx.31mm (included)
M0.8-65T gear: 65T (65 teeth) 0.8mm pitch, diameter is approx.49mm (not included)

Suitable for:
All DSLR cameras, Video cameras

More accurate, stronger, lighter, that is what FOTGA DP500III follow focus pursuit for. Comes with three 0.8m gear (43T/65T) to suit different lens. The crank handle make it convenient for you to control the follow focus from upper.

Features:
Based on MarkII-S, the transmission system of DP500III has made great improvement in accuracy and smoothness.
While ensuring high reliability and stability, it is 16% lighter, more portable to carry.
The gear ring belt suitable for lens of 48 ~ 134mm outer diameter.
The A/B stop makes it fast to switch focus between two items.
φ15mm clamps compatible for universal rod systems.
The speed crank handle(aluminum) will offer a 90°right angle to control the follow focus.
0.8M gears(43T/65T) to fit different lens, can be mounted on both right and left sizes.
Newly added rubber surface, high tolerance to hot/cold temperature, better texture in cold condition.

Features:
The servo follow focus is designed for FeiyuTech AK series stabilizer, such as AK4000, AK2000, etc.
Adjustable gear ring, fit for most of cameras with focus ring on the lens, including camcorders, DSLR and so on.
Supports real time focus, as a good helper for video shooting focus, widely used in microfilming, vlog shhoting and so on.
Connect the stabilizer via USB to control the focusing.
Made of high quality plastic and aluminium alloy material, very durable.
Can be installed quickly, easy to operate.