The iDC PhotoVideo System Zero XL1 Follow-Focus with Viewfinder (for Canon 7D) is a versatile follow-focus system designed to lend cinema-like focus control to your DSLR videos. The system's gearless design means that, unlike most other DSLR follow-focus units, this one doesn't require the dedicated gears to match each lens in your kit. An adjustable focus wheel attaches to one of seven dovetail slots on the sliding focusing plate, which in turn mounts to the dedicated base plate beneath the camera.
The base plate, designed expressly for the Canon 7D, can use any standard quick-release assembly for mounting onto a rig or tripod. It also accommodates iDC PhotoVideo's adapted Hoodman HoodLoupe, included, providing you with a larger viewfinder for even more precise focus. When not in use, the focusing wheel slides away from the lens and locks in place, or the combined baseplate/focusing plate/wheel can be removed as one piece (using an Allen wrench) for easy switching between video and stills shooting.
This XL1 version works with most wide to mid-range telephoto lenses. For smaller prime and telephoto lenses, the Standard kit - with its shorter focusing plate - may be more suitable.