Real-Time Power Monitor UPS HAT for Raspberry Pi This UPS HAT can offer enough time to store the code on the RPi and can also be used as a separate power supply unit for backup Effectively charge the batteries and provide power output from an external power supply Reserves 40-pin header to stack with other Raspberry Pi accessory boards for enhanced applications Compatible with all the Raspberry Pi models such as 4B/3B+/3B/2B/B+/A+/Zero 2W/Zero, etc.