1. The display device is a 4-digit common positive red digital tube.2. The 8-level gray scale of the digital tube is adjustable.3. The control interface level can be 5V or 3.3V.4. Four M2 screw positioning holes for easy installation.5. Control interface: 4 pins in total (GND, VCC, , CLK), GND is ground VCC is the power supply, is the data input and output pin, and CLK is the clock signal pin.Digital tube: 4-digit 0.36-inch digital tube with common anode and score points, with red letters highlighted.Positioning holes: 4 M2 screw positioning holes with a diameter of 2.2MM, making the module easy to install and position.bit to achieve combination between modules.size: 4.2 x 2.4x 1.2cmMaterial: plasticcolour: BluePackage Contents: 1 x moduleOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.