Yes, Telect offers duct extenders for the 6ft Global Seismic frames.  The 6ft duct extender kits come in 5” (0GS034SP-05) or 10” (0GS034SP-10) widths.  Each kit includes the frame base filler, duct cover, and mounting hardware.  If you want Fiber spools to be included, add a "S" at the end of the part number.