Variable Speed Compressors
Panasonic Inverter Compressors can run at a number of desired speeds, depending on how the refrigerator is being used by the consumer. This provides options for quick pull down or freezing, or to run at a very low speed once the cabinet is at a steady state, thereby significantly reducing energy consumption.  

Single Speed Compressors
D Series Compressors are Low Back Pressure (LBP), High efficiency, low noise compressors for Refrigerators and Freezers. S Series Compressors are Low Back Pressure (LBP), compact size, low noise, low vibration Compressors for Refrigerators and Freezers. Q Series Compressors are Mid Back Pressure (MBP)/High Back Pressure (HBP), low noise, high durability Compressors for Refrigerators, Freezers and and Light Commercial.