CyberPower’s CP900AVR has a simple-to-use interface with just two buttons (electricity on/off and mute) and four indicator lights (showing if the device is turned on, when the battery backup kicks in, when AVR is activated, and when there’s a power overload) about the entrance of your unit. Picture: Michael Hession https://judo-history82581.bleepblogs.com/36734735/indicators-on-ups-battery-system-you-should-know