rOtring Isograph Technical Drawing Pen, 0.35 mm This is a high-precision technical pen with a refillable ink reservoir, available in 13 different line widths. Wear-resistant, hard chrome-plated thin tip allows exquisite detail work. Nib is crafted from stainless steel. Push-on sleeve provides easy access to ink helix and fast cleaning. Color coded barrel indicates line width. Refillable ink reservoir is ideal for frequent drawers. Fill from high-density pigment ink bottles available in multiple colors. Ink not included. Wear-resistant, hard chrome-plated thin tip allows exquisite detail work. Nib is crafted from stainless steel. Not for any use on skin, including tattoos.