Jinhao 619 fountain pen ef 0.38 mm tip one blue or black cartridge is sent as shown in the picture. it has a 3.4 mm piston. it is compatible with 3.4 mm cartridges. you can use the cartridge that comes with the pen by removing the piston and replacing it. maximum 10 pieces of this product can be ordered. swordslife reserves the right to cancel orders over 10 units. more than 10 stocks are available to be sold at the campaign price. the seller determines the selling price of the product you have reviewed. this product is not included in the discount campaign. 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.