The Durus Follow Focus is a single rail mount focusing aid tool that can be mounted left or right, at any height, with the focusing head angle adjustable to suit the filmmaker's needs. Because it is machined from 3 aluminum billets, the only plastic used in its construction is the dry-erase focus ring, which is designed for multi-angle viewing and the interchangeable (.8 film pitch) drive gear.The Durus Follow Focus also comes with a lifetime warranty.Kit Includes:15mm Rod Mount0.8 Pitch GearsDry-erase Focus RingFollow Focus Gear Ring (qty 3)Focus Gear Spokes (5 sets of spokes. Each set contains 6 spokes) Includes lengths: 3/8", 1/2", 5 /8", 3/4", 1"