FILMCITY HS-2 Professional Hi-Grade Follow Focus with A/B Hard Stops, Flexible Gear Belt & Speed Crank | for 15mm Rod Support & DSLR Video Camera Stabilizer Shoulder Rig (HS-2) PROFESSIONAL HI-GRADE ALUMINUM CONSTRUCTED follow focus ensures slip-free & accurate focus pulls. INTEGRATED HARD STOPS offer Smooth, Precise and accurate focusing. VARIABLE LOCKING MECHANISM allows quick adjustment of start and end points. INTERCHANGEABLE DRIVE GEAR helps in changing the gear from side to side. MAGNETIC MARKING DISK enables to view your focus marks from various angles.