The GV-IO Box 4 provides 4 inputs and 4 relay outputs. It supports both DC and AC output voltages, and provides a USB port for PC connection. Includes: GV-I/O Box 4 Ports V1.2 x 1. USB Cable (Type A to B) x 1. Terminal Resistor x 1. Power Adapter DC 12V x 1. Software DVD x 1.