This 8 digit seven segment display module is based upon the Maxim MAX7219 LED display driver. The module uses two standard 4 digit seven segment displays to display a total of 8 digits in RED with decimal point. A convenient input and output header allows additional modules to be daisy-chained and controlled with just just 3 digital IO pins. The Maxim MAX7219 driver allows for each segment of up to 8 digits (with decimal point) to be controlled individually from a serial interface. An 8x8 static ram area stores each digit and multiplexing the display is handled automatically. If you plan to use this module with an Arduino board there is a library (HCMAX7219) that allows you to effortlessly display and scroll alphanumeric characters across one or more modules. This can be downloaded from here. Cable is not supplied. If you require a cable, please see our range of dupont cables on our website. Specification: Driver: Maxim MAX7921 Voltage: 4.0 - 5.5V Max current: 180mA (all LEDs on) Min current: 0 .5mA (shutdown mode) Length: 70mm Width: 15mm Height: 18mm (approx)