CyberPower’s CP900AVR has an easy-to-use interface with just two buttons (electricity on/off and mute) and 4 indicator lights (showing in the event the unit is turned on, if the battery backup kicks in, when AVR is activated, and when there’s an influence overload) within the entrance in the device. Photo: https://zane68877.blogadvize.com/44132680/battery-ups-9ah-12v-katzuni-kz12v9-no-further-a-mystery