The ikan F3 Friction Follow Focus is the perfect affordable solution for bringing precision focus to your DSLR video productions. Lightweight, preassembled, and with no need for expensive gears, the F3 mounts easily to your Elements rig or a preexisting 15mm rail system. The high-precision gearbox can then be adjusted to fit just about any small or short focal-length lens, until the rubber wheel presses against your lens' focus ring and, using simple friction, lets you pull focus smoothly and precisely.