An opaque material apposed to the periphery of the subplasmalemmal Cisterns of cochlear outer hair cells.
D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D003051:Cochlea / Q000033:anatomy & histology*; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000648:ultrastructure*; D008465:Mechanoreceptors / Q000648:ultrastructure*; D009940:Organoids / Q000648:ultrastructure*