A protein complex that is located at the ciliary transition zone and consists of tectonic proteins, B9 domain-containing proteins and other proteins. Acts as a barrier that prevents diffusion of transmembrane proteins between the cilia and plasma membranes. In mouse, members of the complex include TCTN1, TCTN2, B9D1, MKS1, CC2D2A and other proteins. (Gene Ontology, GO_0036038)
