Endostar Unique K-files are very special endodontic instruments. Unique K-file has a ‘K file’ configuration in cross section and it has non-standard ISO sizes-so-called ‘half-size’. It helps to match the file to specific clinical case. Using of Unique K-files helps to avoid steps during the root canal preparation. There are following sizes of the instruments: 12,5; 17,5 and 22,5. Endostar Unique K-files are safe instruments with four cutting edges. Traditionally, this group of instruments have been made from stainless steel and they were designed in a shape proposed by Dr Kerr.