Features: Pure Tungsten Electrodes: Pure tungsten has a high work-function which makes it difficult to starts and maintain a stable arc. High burn-off rate results in short service life. Lanthanated Tungsten Electrodes: This material is a fine general purpose non-radioactive replacement for Thoriated. It has perfect ignition performance, low-burn-off rate, perfect re-ignition, and fine service life. Thoriated Tungsten Electrodes: This material is a popular general purpose electrode due to the perfect arc behavior and fine tips life. You can choose different colors according to different needs.