433 MHz RF receiver and quad relay shield
If your next Arduino project needs some kind of remote switching control, this DIY 433MHz RF receiver plus relay shield might be useful for you. It includes a 433.92Mhz RF receiver and four SPDT relays, which allows you to perform wireless control of the devices connected to the relays. Each relay is capable of switching up to 10A @ 250VAC mains power supply.
433MHz RF and relay shield