This is an IIC Serial 2004 LCD module. With this I2C interface LCD module, you will be able to realize data display via only 2 wires. If you already have I2C devices in your project, this LCD module actually cost no more resources at all. It is fantastic for Arduino based project.    

Features:    

        Brand new and high quality    
        LCD display module with green back-light    
        Wide viewing angle and high contrast    
        Built-in industry standard HD44780 equivalent LCD controller    
        Commonly used in: copiers, fax machines, laser printers, industrial test equipment, networking equipment such as routers and storage devices    
        LCM type: Characters   
       I2C Default Address: 0X27 or 0X3F
        Display:  4-lines x 20-characters)
        Operate with 5V DC    
        Module dimension: 98mm x 60.2mm x 11mm
        Viewing area size: 76mm x 26mm