Features: Enhances stability and balance for EF 100 400mm II lens with this durability aluminum alloy tripod mount collar, designed to securely support heavy telephoto setups during extended shoots. Precise engineered with lightweight yet robust aluminum construction, this replacement mount collar ensures optimal weight distribution and compatibility with standard tripods. Ideal for professional photographers and wildlife enthusiasts seeking reliabled support for large telephoto lens during dynamic outdoor or studio . Perfectly suited for capturing fast moving subjects in sports, aviation, or nature photography where lens stability directly impacts image sharpness. The RJ102 tripod collar replacement features a tool less installation design, maintaining seamless integration for EF 100 400mm II while reducing front heavy lens sag Specifications: Item: metal Support 1/4 thread Color: Silver Weight: 77g size about 93x38mm/3.66x1.49in For EF 100 400mm II lens ，RJ102 tripod collar Package Includes: 1PC Tripod collar replacement seat note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.