OptiFans, the company's new DC fan line, are designed for use in everything from personal computers and electronic enclosures to telecomm and industrial equipment. Design refinements in the fan blade and housing and proper bearing selection and mounting techniques are said to minimize noise. Some fans in the series provide optional internal speed control via internal thermistor-controlled circuitry that responds to a change in air temperature by varying motor speed. This option can be used to reduce airflow, acoustic noise and power consumption when high airflow is not needed. The fans range in air flow delivery from 3 cfm for a 40 mm x 40 mm x 7 mm fan to 100 cfm for a 120 mm x 120 mm x 38 mm fan. Prices range from $2 to $5 each, depending on bearing style, motor speed and options.