Cassette, with the aid of a fast and easy algorithm, is able to solve the transport capacities of gravitational rectangular pipes. Supported in-app languages: Albanian (sq); Arabic (ar); Bulgarian (bg); Chinese (zh); Dutch (nl); English (en); Finnish (fi); French (fr); German (de); Greek (el); Hebrew (iw); Hindi (hi); Hungarian (hu); Italian (it); Japanese (ja); Korean (ko);