SainSmart 2 Channel Relay XBee BTBee Shield for Arduino UNO MEGA R3 Mega2560 Duemilanove Nano Robot Use the heavy current relay, AC250V 10A DC30V 10V tacitly use 5V relay Easy to connect RF/Bluetooth wireless port support XBee/BTBee,nRFL2401? CC1101 wireless module. Directly connect outside power supply, convenience support high power switching device 6 electronic bricks ports, 3 servo motor ports