Thank you for contacting Promethean Technical Support.
As the first generation ActivBoards have come to their end-of-life cycle, so have the compatible pens. Accessories and spare parts for these models of boards are not manufactured anymore and we their design specs would be hard to find.
However, we still offer our customers support with their queries.
What we can suggest is to look for these products on online selling sites.
We apologise for not being able to provide more help.