The RCS H-file boasts a wide range of sizes, ranging from No. 15 to No. 80, with the commonly used sizes being No. 15 to No. 40. These files are color-coded starting from No. 15, following a cyclical sequence of white, yellow, red, blue, green, and black, which facilitates doctors in selecting the appropriate size based on the size and shape of the root canal. This highly adaptable feature enables the H-file to be suitable for various types and shapes of root canals, thereby enhancing the success rate and effectiveness of treatment.