Medium (1.0)mm. 50th Birthday. Our Long lasting pen. Now with purple ink! Four ink colors in one pen! Writes black, blue, red, and now with purple! Fun and colorful expression. Convenient way to organize copy. Long-lasting ink. BIC Performance Policy (US and Canada): If you are not satisfied with the performance of this product, please return it to BIC and we will gladly replace it at no cost to you. www.bic.com. Made in France.