[PACKAGE AND SIZE]: Come with 4 pieces of art ruling pens in a pack of 4 sizes, the 4 pens are in length of 4.8/5/5.3/6 inch individually. [RELIABLE MATERIAL]: The point of the art ruling pen is made of iron, durable enough for long time use, the pen-holder is made of high quality plastic, lightweight and comforable for fine line drawing. [ADJUSTABLE PENS ]: You can control the line width by adjusting screws, tightening or loosening them to draw right line, loosen the screws after use to avoid deformation of the line pen. [EASY TO USE ]: Dip the ink in the gap when using. If you want to draw a straight line, the pen must be perpendicular to the paper and draw a horizontal line with even force. [WIDE APPLICATION]: Suitable for fine line drawing, technical drawing, cartography and calligraphy, a perfect tool for both beginners and artists to draw and paint. The nib is covered with wax to prevent rust and sharp danger. High temperature may melt and redness. It is not rusty. It can be wiped off with a damp cloth. If you have any quality problems, please feel free to contact us and it will be resolved as soon as possible.