Optimum®+NiTi Gold Variable Taper Rotary Files are heat-treated The files offer superior resistance against breakage caused by cyclical fatigue and have no rebound Unique heat-treatment technique allows the files to be pre-bent Files have superior canal tracking 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 #C1 21mm Box of 6#C1 21mm Box of 6