Specifications: Classic gym knock for office writing utensils is even thinner and 0.02 inch (0.5 mm) in diameter. Material: Shaft with resin and rubber grip; Body size: Maximum shaft diameter: 0.4 x 5.5 inches (11.6 x 140.1 mm); Body weight: 0.3 oz (9.9 g); Ink color: Black; Ink: Oil-based dye; Refill: K-0.5 cores (BRS-6A-K-BK).