Usually, a lengthened version of an existing model rocket design, used in altitude and duration competition. Scoring is based on altitude multiplied by airframe length. Super-Roc has different length limits for different motor classes. For example; A has a range of 75 to 150 cm, C has a range of 125-250cm. The rockets can be longer but the excess length is not counted into the length factor. In the altitude category the rocket may be recovered in more than one section.