The FocusBee Follow Focus includes a 15mm Lightweight Core Bridge for 15mm rods, a sleek Swing Arm, a 0.8 MOD 43-Teeth Drive Gear, a 35-Teeth Drive Gear, and a Focus Handwheel with Marking Disc that works together to deliver smooth & precise focus adjustments. The swingarm features a 1:1.842 gear ratio enabling broader & smoother focus adjustments & it also works well with the lightweight core bridge by transferring the focus movement from the handwheel mounted on your core bridge to the drive gear that interfaces with your lens. You can mount the Swing Arm on either side of your core bridge's drive transmission to match the position of your lens's focus gear. The 43 Teeth Drive Gear has a finer gear ratio than 35 teeth drive gear, allowing the operator to focus more precisely, especially when working with lenses with narrow field depth. The 35 Teeth Drive Gear delivers a slightly faster & less sensitive focus control, making it useful for wide-angle lenses, especially in fast-paced shooting scenarios. Both gears can be mounted on either side of the Swing Arm. The Focus Handwheel is a conical handwheel with an anti‐slip grip with built-in keyway depression that lets you accurately pull focus without taking your eyes off the action. You can pull focus from both sides by switching the focus unit from one side to another. The handwheel also includes a removable marking disc that can be pre-marked to match specific lenses for rapid lens changes & focus resets. SPECS Construction: High-Grade CNC Aluminum Ratio of Swing Arm: 1:1.842 Numbers of Gears: 0.8 MOD 43 Teeth Drive Gear X 1 0.8 MOD 35 Teeth Drive Gears X 1 Face Width/Diameter: 35 Teeth Drive Gear - 0.4” / 10 Mm 43 Teeth Drive Gear - 0.2” / 6 Mm IN THE BOX Proaim 15mm Lightweight Core Bridge Focus Handwheel Swing Arm with Drive Gear 35 teeth knob 1 x Drive Gear with 43 teeth 1x L- type Allen key (Size: - 2.5mm) Pouch