NiTi thermal active arch wire react to heat in a unique way: Cold temperatures make the arch wire extremely malleable and able to create unique bends in the archwire without kinking. Once the wire begins to heat up, it restores its original form, putting the wire to work as soon as it is engaged. - Size: 0.018x0.025 Inch. - Type: NiTi. - Square. - Lower. **For further product information, please contact Chat Support**