Feature:1. Flexible Configuration: I2C interface expands 16 channels of IO, flexible configuration of input and output, compatible with 5V/3.3V2. For MicroChip's MCP23017 Chip: The module is a 16 way 1 expansion module with I2C interface, using for MicroChip's MCP23017 chip3. Complete Functions: The chip has complete functions, each 10 can be configured as input or output, and the pull up resistor can be set, and the interrupt function can be enabled for the 10 configured as input4. High Speed IC Interface: MCP23017 is a high speed IC interface, supporting 100KHz, 400KHz, 1.7MHz IIC frequency5. A Maximum of 128 IO Expansion: The chip has 3 address pins, 8 different addresses can be set, so 8 modules can be connected through two IC buses to achieve a maximum of 128 IO expansionSpecification:Item Type: IO Extension ModuleWorking Voltage: 3V~5.5VFrequency: Support 100Khz, 400Khz, 1.7MhzTemperature Rating: -40~125Board Size: Approx. 66 x 18mm / 2.6 x 0.71inIO interface has strong driving ability, sink current and source current up to 25mA.Package List:1 x IO Extension Module2 x Pin Header