ITEM NAME:5V 2 Channel Driver-Free USB Smart Control Switch Relay Module for PC Product Description Description: Features: Onboard square USB interface, stable connection. Use imported high-performance USB control chip. Military grade PCB board production. Specification: Appliance: Industrial Control Work Voltage: 5V Max Load: AC 250V 10A, DC 30V 10A Connection: NC/COM/NO Hole Diameter: 3mm Net Weight: approx. 31 g Size: approx. 63 X 40 X 17 mm/2.48 X 1.57 X 0.67 in Included: 1 X Relay Module.Included:1 X Relay Module. Onboard square USB interface, stable connection. Max Load: AC 250V 10A, DC 30V 10A. Connection: NC/COM/NO. Military grade PCB board production. If item is defective after 3 months, you can still send it back to us.