Platinum Refillable Silver 'Converter' Cartridge

For those unfamiliar with a 'converter', these Platinum cartridges can be refilled from any suitable fountain pen ink bottle. This means not only that you can choose from an endless selection of coloured ink, across all brands, but also that you will never again depend on buying another cartridge. Indeed, this refilling method is far more economical - but bear in mind that it can be messier and probably not the best option when on the go.