In boxing, a weight class is a measurement weight range for boxers. The lower limit of a weight class is equal to the upper weight limit of the class below it. The top class, with no upper limit, is called heavyweight in professional boxing and super heavyweight in amateur boxing. A boxing match is usually scheduled for a fixed weight class, and each boxer's weight must not exceed the upper limit. Although professional boxers may fight above their weight class, an amateur boxer's weight must not fall below the lower limit. A nonstandard weight limit is called a catchweight.