Seeed relay shield for arduino v3 0 seeed studio 103030009 p the arduino relay shield from seeed studio gives you 4 relays that will switch 7a at 35v dc each easily enough for most applications screw terminals are provided for the connections to the device being switched and an led indicator shows the status of each relay s normally open no contacts your arduino can control the board via 4 digital output pins giving you the opportunity to control multiple relay boards pcbs with high vo