CyberPower’s CP900AVR has a straightforward-to-use interface with just two buttons (ability on/off and mute) and four indicator lights (demonstrating in the event the unit is turned on, once the battery backup kicks in, when AVR is activated, and when there’s an influence overload) to the front on the device. Photo: https://josuez4klm.blog5star.com/36797522/5-simple-statements-about-ups-battery-tester-explained