Description This modern Esterbrook #6 steel Extra Fine Flex Jowo nib unit in Silver is a complete all-in-one nib and feed unit which screws into your modern Esterbrook Estie pen, and is designed like Esterbrook nibs of old. ** Please note that this nib will not fit original vintage Esterbrook pens. ** Additional Esterbrook fountain pen nib units are available separately as well. Make sure to remove the cartridge or converter in the barrel before unscrewing and replacing the nib unit. We offer Free Shipping on all orders over $59 for US customers, and for orders over $250 for our Canadian customers.