A nine-bladed, propeller-like protein complex that links the distal end of the basal body and the cilium to the plasma membrane. Functions in protein sorting and gating (i.e. active and passive transport of proteins in and out of the cilium). [ http://www.ncbi.nlm.nih.gov/pubmed/5064817 http://www.ncbi.nlm.nih.gov/pubmed/5335827 http://www.ncbi.nlm.nih.gov/pubmed/24231678 http://www.ncbi.nlm.nih.gov/pubmed/22653444 ]