NOYITO 4-Channel 12V Computer USB Control Switch Relay Module Drive-Free Relay Module Plug and Play Suitable for PC Smart Controller: Amazon.com: Industrial & Scientific
SainSmart USB 4 Channel DC 12V Relay Module Automation for Arduino Raspberry Pi DSP AVR PIC ARM: Usb Relay Board: Amazon.com: Industrial & Scientific
USB Relay Controller - High Power USB Relays for Industrial Applications