4-Digit Tube Display Module:
Can be used to display decimal, letters, etc.
The display device is a 4-digit bright red digital tube.
There are 4 pins:
GND to ground
VCC for power
DIO for data input and output pins
CLK for clock signal pins.
Working voltage:3.3V/5V DC
Working current:30/80MA
LED brightness is adjustable:digital tube 8-level gray level is adjustable