Product Description: 1.Onboard square USB port,and connection is stable. 2.Use import high-performance USB controlling chip 3.Use genuine relay 4.Military level PCB board workmanship 5.PCB size: 56.5mm*24.9mm 6.Fixed hole size:3mm,central moment:52.2mm*20.6mm Product Parameter: 1.Realy Voltage:5V, maximum voltage:250V. AC 10A 30V, DC 10A 2.Controlling Port Connection Way:NC/COM/NO