This does not show you how it will rename the files. It is a very poor and confused interface which gives you no intuitive information about how to do what you need to do. Seems to be written by a programmer for geeks, not normal users AND it is not specific. For example, it says Truncate, you choose it, then it says how many characters and you enter a number and then it changes the names of the files without further warning or clarification or even asking the user how to truncate. Should it truncate from the end of the file name or the beginning? This is a really dangerous app as it can do permanent damage to your file structure.