Conforms to ASTM F288-96, Type 1A. Diameter: 0.0250'' (0.635 millimeters) Length: 20+ feet 99.95% pure tungsten. Wire is clean and straightened. Finish is electropolished. Uses of this wire include medical devices, LEEP and LEED electrodes, corona generation, vacuum heating elements, filaments, and thermionic emitters.