This is LED mini 0.56 inch digital voltmeter panel meter DC 0-99.9V 3 wire
Module name : voltage display module
Measurement accuracy : 0.1%
Refresh rate : About 200ms
Display : three 0.56 inch digital tube
Measuring range : 0V-99.9V
Power supply range : DC 4.5V-30V
Operating current : less than 8mA

Display color : Blue， green
Storage Temperature : -10 degree to +65 degree
Input impedance : approximately 100K
External dimensions : 4.7cm x 2.8cm x 2.6cm /1.85inch x 1.1inch x 1.0inch
Weight : 14g

Red line for "+"， black line for "-".
Yellow line for "test" (0---99.9V)

Package included :

1 X Digital voltmeter