8 X Schmidt 635M Mini Ball Pen D1 size Refills &ndash; BLUE Ink and one removable black end cap. 8 Pack of Schmidt 635M Blue Refills Equipped with Nickel Silver Tip and Stainless-Steel Ball Schmidt D1 Size Blue Refill Medium Tip Includes one removable Black Plastic End Cap Lamy M21 and Cross 8518-4 Compatible Length: 2.6 inch (66.0mm)