RRS Really Right Stuff LCF-101 Replacement Foot for Sony FE 100-400mm f/4.5-5.6 GM OSS and FE 70-200mm f/2.8 GM OSS Lenses This is a tripod foot (lens foot) compatible with Sony lenses. By replacing the original foot, it can be attached to an Arca-Swiss compatible clamp. Compatible lenses are as follows: ● Sony FE 100-400mm f/4.5-5.6 GM OSS ● Sony FE 70-200mm f/2.8 GM OSS I purchased this through personal import from the US official website. I have used it for several years, and while there is a sense of use, there are no wobbles or malfunctions with the main body.