SMAKN&reg; 3.3V To 5V 5V To 3.3V 4 Channel IIC I2C Logic Level Converter Bi-Directional Module 5V to 3.3V Compatible With Arduino 4MOS tube to achieve four 3V and 5V level of two-way conversion. With anti-reverse polarity power input protection, integrated 3.3VLDO, and provide external current is not greater than 150mA. With power indicator light, working or not clear. Can achieve UART, IIC, 1-wire, SPI bus signals and other 3V-5V level two-way conversion.