Piece of plastic pipe with internal diameter 36 mm or 1 7/16" will resolve this issue (cost $0-$20). Another option is to buy Festool's or non Festool 36mm hose. 36 mm hoses work much better for saws, routers, planer or just for floor clean up $20-$150). The third option is to buy one of the Festool's clean up sets. They usually go with systainer, 36 mm hose and bunch of other attachments ($140-$235).
Regards,
VictorL