The Clutch is a tough pen made for tough jobs. Its hefty hexagonal finger grip design ensures that you will maintain a solid grasp on the pen even when wearing thick gloves, and its composition of black anodized aluminum provides both a sturdy and light-weight feel in hand. All metal , 12 mm (.520 inch) diameter. Contains a #PR4 Black Ink, Medium Point Pressurized Fisher Space Pen Refill. Gift packed!