welcome to our store! Features: These soldering iron heating elements are made of ceramic materials, two-line heating mode, stable quality, superior performance. High-quality heating cores are resistant to corrosion, oxidation acid, alkali, high temperature, and have a long service life. Optimal performance, fast heating, high thermal efficiency, rapid heat conduction. Good insulation, anti-static, no electrical leakage, no flame, to ensure safety. Small size, light weight, 10 pieces in this set suitable for internal heating soldering irons. Specifications: Type: Internal Heating Material: Ceramic Length: 8.3cm/3.26in Diameter: 0.4cm/0.15in Input Voltage: 220V (50Hz) Power: 20W Resistance: >100MΩ Package Includes: 10 x Heating Elements Please allow minor errors due to manual measurement and different monitors. (Customer satisfaction is our top priority. If you find any product problems after receiving the goods, such as damage or incorrect quantity, please contact us immediately. We will do our best to provide you with satisfactory customer service. Thank you for meeting me. I hope this helps you. Wish you a happy life.