This IO expansion board is compatible with Arduino UNO / Leonardo / Mega2560. It is a connection bridge between the electronic building block module and the Arduino board. It extends SPI interface UART interface I2C interface PWM interface and analog interface of Arduino board so DIY enthusiasts Arduino interactive designers can quickly attach the modules to the Arduino board and accelerate project development progress. Features: 1. Compatible with Arduino UNO R3 Leonardo R3 Mega2560 R3 2. On-board reset circuit power and reset indicator. 3. The Pin headers is 2.54mm pitch