A pure sine wave indicates an output voltage whose waveform is virtually identical to the ideal sine wave from the grid. Such an output is provided by high quality inverters and on-line UPS and is suitable for equipment with transformers, induction motors, pumps, audio equipment and for power supplies with active PFC. Benefits include lower noise and vibration, less heating of windings and power elements, higher efficiency under real loads and less risk of false faults. Sensitive instruments, instrumentation and servers typically require a clean sinusoid for proper operation and long life. The disadvantages can be higher purchase price and more complex topologies that place demands on control and cooling. For powering mixed and sensitive loads, pure sine wave is the recommended standard.