Features: Meet your using needs, and you can share them with your friends. Made form quality material, sturdy and stable, reliable, not easy to break or fade, can be quickly dried, which will serve you for a long time. You can use these circuit pens to check your circuit. After you have drawn the line, you can put a light over the line, if your line is correct, the light will light up. Easy to Use: you can shake conductive ink pen before using the pen, without pausing in the drawing process. When the ink dries, you can put on the light. Suitable for circuit, science experiment, DIY science projects, and can be applied for most people to use. Specifications: Capacity: 3g/6g Size: As Shown in the Pictures Note: Please allow 1-2cm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Conductive Pen