Optimum®+NiTi Variable Taper Rotary Files are designed to safely and efficiently shape the canal Made of premium USA-sourced super-elastic Nickel Titanium wire The design is ideal for simple straight canals calcified canals and removing gutta-percha Files have a 3 fluted file design and calibration rings for setting accurate working lengths Standard file sizes for easy brand comparison #C2 31mm Box of 6