A fiber optic cassette and system is disclosed. The cassette is mountable on a tray in parallel to and adjacent to at least one other like cassette. Each cassette comprises an housing having an axis, a first optic fiber connector-receiving receptacle along a housing front face for receiving at least one first optic fiber, a second optic fiber connector-receiving receptacle along a housing rear face for receiving at least one second optic fiber, and at least one third optic fiber within the housing, the third optic fibers interconnecting respective ones of the first optic fibers and the second optic fibers. The rear optic fiber connector-receiving receptacle is moveable in a horizontal plane between a first position wherein the rear receptacle is arranged at a first angle to the axis and a second position wherein the rear receptacle is arranged at a second angle to the axis.