Jinhao 619 water blue fountain pen ef 0.38 mm nib it has a 3.4 mm piston. it is compatible with 3.4 mm cartridges. one blue or black cartridge is sent as shown in the picture. maximum 10 pieces of this product can be ordered. swordslife reserves the right to cancel orders over 10 units. more than 10 stocks are offered to be sold at the campaign price. the seller determines the selling price of the product you have examined. a product can be sold by more than one seller. sellers of products offered for sale by more than one seller are listed according to the price they set for the product, seller ratings, delivery status, promotions on the products, whether the cargo is free or not, whether the products can be delivered with fast delivery, and the stock and categories of the products. Improved version for clearer understanding and better search visibility. Suitable for users seeking detailed and reliable product information.