The ECM Outdoor Motor maintains its high efficiency across a range of operating speeds, which results in a significant reduction in energy use when the motor is run at reduced speeds. This makes the ECM Motor ideal for use in creating two-stage outdoor compressors and heat pump-type units. In addition to reducing electrical use, two-stage compressors feature enhanced humidity removal, less temperature swing between cycles, more even temperatures throughout the home, and quieter equipment operation.IMPORTANT: Heating, ventilation, air conditioning or refrigeration parts and accessories should only be installed by qualified technicians. Failure to understand and follow the manufacturer's installation and use instructions may result in fire or explosion, electric shock, property damage, injury or loss of life. It is your responsibility to seek professional advice when installing and using these parts and accessories. **Actual Product may vary from product image. **