TWSBI Diamond 580 Red Blue Transparent (RBT) 100th Anniversary of Republic of China Fountain PenImproved grip and end barrel section compared to 540 580 has increased ink capacity, about 30% more than 530 580 has improved the smoothness of cap thread turning 580 shows you our promise on continuous product improvement on small details Please note: ink is not included The idea behind the TWSBI Diamond 530, 540, and 580 was to go back to basics and capture the simplicity and elegance of traditional writing instruments. In recent years, the