Components: LCD display with i2c serial interface backpack; LCD screen can display 2-lines x 16-characters; The i2c LCD adapter built-in industry standard equivalent LCD controller Default Address: 0 x 27 for PCF8574T chip; 0 x 3F for PCF8574AT chip; Please kindly check chip of i2c interface; ( Please remember to download LiquidCrystal I2C library on GitHub before uploading code to control board) Compatibility: LCD display with I2C serial interface is compatible with for and ; Working voltage: 5V; To come with a potentiometer, which is applied to adjust backlight and contrast; How to wire: GND-GND; VCC-VCC; SDA-A4; SCL-A5 Application: LCD module is applied to display characters, letters, numbers, real time clock and temperature Display function: LCD display with I2C serial interface can be applied to display real time clock, temperature, humidity and so on; (A potentiometer is also necessary to adjust contrast; Working Voltage: Only 5V) colour:Blue+black Material:plastic Package Contents: 4 x LCD display 4 x I2 C serial interface Only above package content, other products are not included. Note: Light and different displays may cause color of item in picture a little different from real thing. The measurement allowed error is +/- 1-3cm.