This Zelio Logic SR3 discovery pack compact smart relay / programmable controller uses a supply voltage of 24V direct current. It has 26 inputs / outputs with screw-clamp terminals and has an integrated LCD display. It also offers simple programming, display and diagnosing of malfunctions display and navigation buttons. This discovery package includes one copy of Zelio Soft and one USB cable to connect the relay to your PC. Its simple ladder programming makes it adapted for non-specialists.