I just realized that I lost the tripod mount ring for my Canon 100-400mm lens. It must have fallen out of my camera bag on a recent spotting trip. It seems as if they are sold as pricey spare parts by Canon (180 $).
When trying to find a used one on ebay I came across the replicas from Asia.
Has anybody ever used one? It is well-known fact that Canon charges a premium for accessories but the price difference is more than significant.
Also, is it correct that the EF 70-200L 2,8 uses the same mount ring (B(W)) as the 100-400?
Thanks

Stefan