The Relay Shield is an Arduino compatible smart module with 4 mechanical relays providing an easy way to control high voltage. Support 4-way 3A relay control, xbee wireless module.Independent external power supply and optocoupler isolation, effectively avoid electromagnetic interference from the accused devices.
Note:
      Take care the pins on the Shield should not be touched with USB connector of Arduino UNO when they are connected.
Features:

• External power supply voltage: 7 ~ 12V (> 200mA)
• Relay Max Switching Voltage: 240VAC/60VDC
• Relay Max Switching Current: 5A
• Contact load: 1A 250VAC, 3A 120VA / 24VDC
• Number of relays: 4
• Wireless output interface: (serial) xbee / Bluetooth Bee / Wireless Programming Module
• Arduino occupied ports: (relay) Digital 2,3,4,5, (wireless module) Digital 0,1

Package Including:

• 1pcs Four-channel 5V Relay Shield V1.3 for Arduino