It is ultra-small step up booster, converting 0.9V-5V to 5V.
Use for charge of smartphones, power supply for circuit boards to 5V, digital products supply.
Onboard have terminal block for input and USB-A socket for output 5V.
LED (green) power indicator.
Input voltage: DC 0.9V ~ 5V
Output voltage: DC 5V
Output current: 500mA(max)
Conversion efficiency: 96% (max)
1 x Converter