Convenience. Interface Selection: to choose SPI or IIC interface through R3, R4, R5 For IIC communication, it is necessary to move the resistor on R4 to R3, and R5 is soldered with 0 ohm resistor. SPI communication or I2C communication can be switched by configuring three resistors R3 R4 R5 Driver IC: SSD1309 Resolution: 128 x 64 SPI interface definition: 1.GND (power ground) 2.VCC (power supply positive) 3.SCL (clock line) 4.SDA (data line) 5.RES (reset line) 6.DC (data / ) 7. (chip select) Types: white font Colour:blue Material:plastic Size:Diagonal Screen Size: 2.42 inch Package Contents: 4 x Display Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.