DSLRKIT Tripod Mount Ring A (W) for Canon 70-200mm f/4L IS USM The perfect color as the original lens. Advanced CNC processing,High quality aluminum baking painted surface. Suitable for Canon EF 70-200mm f/4L USM, Canon EF 70-200mm f/4L IS USM, Canon EF 400mm f/5.6L USM. Product specifications: Ring inner diameter: 65mm. Ring width: 18mm. Ring thickness: 4-8mm. Color: White. The UNC (Unified National Coarse Thread) is 1/4" and 3/8".