Hi,you can have a look at your cardboard box which is the biggest size, then tell the packaging manufacturer the size. Then the carton can be generic. The suitable size of general carton sealer in accord with packaging industry standard is L320~500*W200~500*H180~500.If the maximum or minimum size of your cardboard boxes is beyond this range, it belongs to the non standard models, and you need pay more money for suitable carton sealer.The other is not an issue.