Question about Sigma 100-400mm f/5.0-6.3 DG DN OS, Sony E

It is the type TS-111 which also fits the Sigma 1.4/105. Strangely, however, it is hard to find. Actually, it should also be available in the shop. I can't understand why this is not the case. At Toppreise, a shop is displayed that carries the tripod clamp.