USPRO&reg; IIC/I2C/TWI Serial 2004 20x4 LCD Display Module Shield Yellow Back Light for Arduino UNO MEGA R3 This product is the complete LCD screen with the Serial board on the back to allow serial communication. Adopts premium LCD 2004, yellow backlight with green letters, for clear display; Dedicated IIC bus control, only takes two IOs. Adjustable contrast and backlight controlled; Backlight can be controlled through jumper or program control. Supply Voltage: 5V Application: DIY Arduino based project