V06 #OO-14-17-20-25-30 L21 Non-Sterile Endodontic Niti 6 File Kit. Heat treated to increase file flexibility. System insures root canal navigation without ledging, transportation or zipping, even in the most curved canals. SS White's proprietary processing reduces shape memory, allowing them to follow the natural contours of the canal while also adding inherent strength and flexibility.