Enjoy smooth, seamless lens operation underwater when using Ikelite DSLR camera housings, thanks to this Zoom/Focus Clamp and Gear Sleeve Set designed for lenses with zoom or focus rings measuring up to 2.8" in diameter. The clamp and sleeve are lightweight and can be installed easily on the lens before the lens port is secured onto the housing. No modification to the lens is required. The clear sleeve acts as a gear and has teeth that mesh with the teeth on the lens ring. For compatibility, please see the Port Chart.