Supports stable ink flow, high line quality, high speed, and line drawing. Even without disassembling the nib, simply remove the push-on cover and clean with water. The cap is double air tight with an air tight seal to prevent ink from drying up. Uses an isograph-exclusive ink with high concentration of fine particulate pigments that are highly water resistant and long archival quality. Shaft diameter: 0.5 inches (12 mm); Total length: 5.1 inches (130 mm); Weight: 0.4 oz (12 g); Shipping box specifications: Size (H x W x H): 5.5 x 1.5 inches (140 x 38 x 20 mm); Weight: 0.8 oz (22 g); Wire width: 0.2 g); Color code: ISO wire width: 0 oz (0.0 oz (0.0 oz (2 g); *Color code, ISO wire width: 0.0 g).