Orion Fans has seven standard frame sizes for the sealed sleeve fans. All of these DC models are available in two voltages. Fan sizes range from the smallest with a 40 mm frame size and a 10 mm installation depth, up to the largest fan at 120 by 38 mm. The smallest fans have the lowest airflow and are the most quiet, although all of the sealed sleeve fans are quieter than comparable ball-bearing fans. Other sizes, speeds, and voltages may be available by special request.