USB control relay module using imported parallel bi-directional FIFO data transmission USB control chip and dedicated relay driven ULN2803 chip, relay work more stable, with a wiring terminal, connected to the 12V power, even if the computer shutdown or USB is pulled from the computer, relay can also be to maintain the set state. Input voltage: DC 9-12 V, input current: > 800mA, connection mode: NC/COM/NO; Relay parameters: control Maximum AC 250V, 10A AC load and maximum DC 30V 10A DC load; environmental temperature: 0-80 degree.