As we Canadians have not had access to Parker or Waterman products for the past two years, the availability of proprietary Parker cartridges has been an issue for the customers we serve at our retail location. We advise using Lamy as they fit and are slightly shorter than Parker/Aurora and have a greater range of colours. BTW early Dupont cartridges looked like short internationals, but the nipple was the same dimensions as the Parker/Aurora/Lamy sizes.