This is the mini USB meter. It can measure voltage, current, power and capacity.
It adopts the OLED screen, it can clearly display all the data. And it display two colors font, white and blue.
It has three functions:Screen rotation,Power-down storage andOver-voltage and Under-voltage reminding.
Technical Parameters:

Weight: 9g （package 25g）

Font color: Blue/White

Display mode: 0.91" OLED screen

Physical size: 43x 20 x 10 mm (L*W* H)

Voltage measurement range: DC3.50 -9.99V

Voltage accuracy: ± (0.3% + 1words)

Current measurement range: DC0.00-3.00A

Current accuracy: ± (0.5% + 2words)

Power measurement range: 0-30.00W

Capacity measurement range: 0-99999mAh

Function description:
Screen rotation function:Press the button on the back, the display interface can rotate 180 degree for being observed easily when you insert it into different side usb of the computer, and automatic memory for the next boot mode.

ower-down storage function:When power off, the accumulated MAH will be automatically stored. The stored MAH is blinking displayed after the boot. When the new MAH is up to 1 MAH, the stored MAH will be covered, and thevalueswillstartover.
Counting the capacity and efficiency of the mobile power supply battery:
Ah data x output voltage ÷battery voltage ÷ efficiency = mobile power supply battery Ah (output voltage is typically 5V, the battery voltage is generally based on 3.7V, typically by 85-90% efficiency)
Over-voltage and Under-voltage reminding:When the voltage is over 5.3V (less than 4.7V), the arrow ˆ (ˇ) will be flashing