Standard Raspberry Pi 40PIN GPIO extension header, supports Raspberry Pi series boards I2C bus communication, monitoring the batteries voltage, current, power, and remaining capacity in real time; Batteries warning indicators, easy to check if the battery is connected correctly Multi battery protection circuits: over charge/discharge protection, over current protection, short circuit protection, and reverse protection, along with the equalizing charge feature, more safe and stable Onboard5V regulator, up to 2.5A continuous output current; 5V USB output, convenient for powering other boards Comes with development resources and manual: www.waveshare.com/wiki/UPS_HAT