Two rollers twill direction: one is positive and the other one is negative. Comes with fine, medium,and coarse diamond knurls. The mechanical process metal knob or other work at the appearance of rolling pattern for anti-slip. Rigidity, wear resistance, anti-demolition damage strength. Anti-rust resistant, high processing efficiency. High strength and hardness. Knurling figure: approx 0.5mm, 1.0mm, 2.0mm Knurling diameter: approx 20mm/0.79 inch 0.5mm Diagonal Linear Knurling : Knurling pitch: 0.5mm Net pulley diameter: approx 26mm/1.02 inch Hole diameter: approx. 10mm/0.39 inch Hanawa thickness: approx. 8mm/0.31 inch 1mm Diagonal Linear Knurling : Knurling pitch: 1.0mm Knurled outer diameter: approx 26mm/1.02 inch Hole diameter: approx 10mm/0.39 inch Knurled thickness: approx 8mm/0.31 inch 2mm Diagonal Linear Knurling : Knurling pitch: 2.0mm Knurled outer diameter: approx 26mm/1.02 inch Hole diameter: approx 10mm/0.39 inch Knurled thickness: approx 8mm/0.31 inch size: 25x8mm/0.98x0.31 inch (Outer Diameter x Thickness) Material:steel colour:black Package Contents: 1 * handle 6 * Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.