Description: - This version of backpack is designed for two dual 14-segment "Alphanumeric" displays. - These 14-segment displays normally require 18 pins (4 'characters' and 14 total segments each) . - This backpack solves the annoyance of using 18 pins or a bunch of chips by having an I2C constant-current matrix controller sit neatly on the back of the PCB. - The controller chip takes care of everything, drawing all s in the background. Specification: - Selling Points: LED display I2C control control. - Size: approx.7 x 28.4 x 12.4mm / 1.99 x 1.12 x 0.49inch Package Includes: 5 Pieces Digital Display Module : Please allow 1-3mm error due to manual measurement. pls make sure you mind before you purchase. might be a little different from the actual product due to color display of different . Thanks for your understanding and enjoy your shopping moment.