@juryaan: These are indeed hard to find here in Holland. One day I was googling and found them at toolstation.co.uk. So I went to toolstation.nl and amazingly they were not listed. I sent an email to toolstation with the question how to order them and they answered that it was not possible 🙁 Now I have ordered them from amazon.co.uk and this week they will arrive. I have no clue what’s wrong with toolstation.