Gikfun 4 Channel IIC I2C Logic Level Converter Bi-Directional Module For Arduino EK1474 IIC I2C Logic Level Converter Bi-Directional Module 5V to 3.3V For Arduino When MCU and 3.3 V device module is connected , 5 V and 3.3 V TTL level mutual transfer is very convenient Logic Level Converter, 3.3V 5V TTL level bidirectional transfers