Orion Fans offers a variety of options for the sealed sleeve fans. Tachometer output provides a means of monitoring the fan’s rotational speed, indicating if it falls below a specified RPM and is providing less cooling. Locked-rotor alarms indicate if a fan has stopped operating, thereby avoiding potential overheating situations. Thermal control adjusts the fan’s speed relative to the temperature inside the enclosure, allowing for a more optimized performance. PWM input varies the fan speed and allows for higher efficiency. Other voltages and speeds may be available by special request.