EXMAX Hot Quick Release Tripod Mount Collar Ring For Canon EF 70-300mm f/4.0-5.6 L IS USM Lens Suitable for Canon EF 70-300mm f/4-5.6L IS USM. Ring inner diameter: 81.25mm, Ring width: 18mm, Ring thickness: 4.5-8mm, Color:white with light yellow Made by metal with very high quality. The third party special design, perfect conformity in color and surface qualities. 100% Brand new