The MOD-IO2 is similar to the MOD-IO but is smaller, with only two relays, does not have opto-isolation, requires a stricter power input, and uses a PIC microcontroller instead of an AVR.
This is a stackable (or rather, chainable) development board which adds relays and GPIOs to any development board that has a UEXT interface. It makes for an easy way to add two relays and seven GPIOs to your system. It has both a male and a female UEXT connector, allowing multiple MOD-IO2 boards to be chained together so you can add as many inputs and outputs as you want. MOD-IO2 has a PIC16F1503 microcontroller, and the firmware is available for modification.