Description : Bi - directional logic level converter is a small device that safely steps down 5V signals to 3V AND steps up 3V to 5V at the same time . This level converter also works with 2 . 8V and 1 . 8V devices . You can successfully set your high and low voltages and step up and down between them safely on the same channel . Each level converter has the capability of converting 4 pins on the high side to 4 pins on the low side with two inputs and two outputs provided for each side . The level converter is very easy to use . The board needs to be powered from the two voltages sources ( high voltage and low voltage ) that your system is using . Dimensions : 1 . 5 x 1cm Package Includes :(2 Pack) 5 Pieces 4 Channel IIC I2C Logic Level Converter 10 Pieces Pin