Features: Suitable for Canon EF 70-200mm f/4L USM, for Canon EF 70-200mm f/4L IS USM, for Canon EF 300mm f/4L USM, for Canon EF 400mm f/5.6L USM. Aluminum alloy construction, anti-rust and lightweight, durable to use. Easy to install with a fixing screw stud and convenient to use. It helps you fix and balance your tele lens which is heavy or long hanging off the front of camera. Nice accessory for photography lovers, bringing you better shooting experiences. Specification: Condition: 100% Brand New Material: Aluminum Alloy Color: Shown as pictures Base Mount Interface: UNC 1/4inch Diameter: Approx. 7cm / 2.7in Inner Diameter: Approx. 6.5cm / 2.5in Weight: Approx. 122g Packing List: 1 * Lens Tripod Mount Ring Other devices on pictures are not included.