Roll-Di is a direction indicator for roll screen curtain users. Many people get confused with which string of the curtain to pull, in order to make the curtain go up or down. As a result, people frequently make the mistake of pulling the wrong string. Roll-Di was designed to prevent those repetitive mistakes. Roll-Di can be simply hung at the bottom of the string and tells which side of the string to pull to achieve the desired position of the curtain. Roll-Di is composed of “up” and “down” arrows. By matching the “up” arrow with the string that makes the curtain go up, and attaching the two parts of Roll-Di with the embedded magnets, users will not be confused.