PROAIM Flip Precise Adjustable Follow Focus with Hard Stops, Flexible Gear Belt for DSLR Video Nikon Canon Sony DV/Camcorder/Film/Video Cameras, Fits 15mm Rod Mounts, Shoulder Supports (FF-FLP) CNC MADE DSLR FOLLOW FOCUS with zero backlash is compatible with most of the lenses COMPACT FOLLOW FOCUS for slip-free, accurate and repeatable focus movement INTEGRATED HARD STOPS ensures quick focus racking between two focus points FLIPPABLE GEARBOX on both sides allows Left-Hand or Right-Hand Operation for ease. VARIABLE LOCKING MECHANISM allows quick adjustment of start and end points.