The Relay Shield based on four high-quality relays that can control up to 30VDC or 250VAC loads to Maduino or Arduino boards. It provides NO (Normally Open) / NC (Normally Closed) interface. It could be a nice solution for controlling devices that could not be directly controlled by Arduino's Digital I/O ports.
Note: Exercise caution when dealing with AC. Get help from a certified electrician.
Based on those Maduino solutions, Makerfabs can also help to customize those boards with customer’s special requests. Contact sales@makerfabs.com for detailed info and further discussion.
More detail you can read our PCB Design and PCBA Turnkey Solution.