Bay windows and corner window angle sections for the Kirsch 9046 Architrac system. Makes possible a hand traversing track from side to side of your window. You can open from center to each side or from left side to right side and reverse. Use splice 9646-061 to connect sides to straight sections and be sure support are used in the bend section for support This is a ceiling mount or recessed ceiling mount product. Priced and sold each.