CyberPower’s CP900AVR has a straightforward-to-use interface with just two buttons (energy on/off and mute) and four indicator lights (displaying in the event the device is turned on, once the battery backup kicks in, when AVR is activated, and when there’s a power overload) within the front on the unit. Photo: https://taifudo-bodyguard26936.rimmablog.com/35329324/5-tips-about-ups-battery-backup-calculator-you-can-use-today