Product Name: Acroball T Series 03 Oil-based Ballpoint Pen, Method: Knock-type, Ball Diameter: 0.01 inch (0.3 mm), Ink: Acro Ink (low viscosity oil-based ink), Ink Color: Black, Body Color: Gunmetal, Size: Maximum Diameter: 0.4 inches (11.3 mm), Total Length: 5.6 inches (142 mm)