The D|Focus V4 Follow Focus from D|Focus Systems is a follow focus with an industry standard, 32 pitch (0.8 mod) drive gear and a machined aluminum, single rod clamp. The "open gearbox" design is reversible and features custom manufactured hybrid gears, with plastic teeth molded over an aluminum hub. An accessory port on the focus knob enables the use of industry standard whips and speed cranks. Among various upgrades from previous versions, the V4 uses a removable marking disc, which makes the disc easier to clean or replace. The included lens gear features standard 32 pitch 0.8 mod teeth, and can fit on almost any lens upto 86 mm in diameter.The D/Focus Systems D/Gear Follow Focus Gear Ring is a universal gear ring that will let you use almost any-sized lens with your follow focus. Four sets of legs, each of a different length, come included and serve as the means to fitting a lens on the inside of the D/Gear. The legs attach on the inside similar to how spikes do on the wheel of a bicycle. A lens positions in the center of the wheel, where the spikes meet, and is pressed tight into that center by the spikes. Then you can apply your follow focus onto the exterior of the D/Gear and pull focus. D/Gear is compatible with any standard follow focus. The D/Rails: BMCC Baseplate from D\\Focus Systems is a 10 oz lightweight baseplate designed specifically for the Blackmagic Cinema Camera. It features 1/4" and 3/8" tripod mount threads on the bottom and supports optional 15mm rods so you can add a follow-focus, matte box, and other accessories. The camera base doesn't block the Blackmagic Camera vents and is rubber-padded to better hold the camera. It has a large thumb nut underneath for tool-less camera mounting and a locking pin on top to prevent camera rotation. The camera mounting screw is standard 1/4"-20. This is a pair of 15mm Aluminum Rods from D Focus Systems 6" long, hollow, non-threaded, and in black.