KMtronic USB 4 Relay Board - RS232 Serial Controlled PCB : Amazon.de: Electronics & Photo
USB Relay Controller - One Channel - PCB
KMtronic Ltd: LAN Ethernet IP 8 channels WEB Relay board
KMtronic Ltd: Raspberry Pi DIY Home Automation Starter Kit - USB Relay
KMTronic LAN Ethernet IP 8 channels WEB Relay board BOX 3800500266077 | eBay
GitHub - donatmarko/kmtronic-usb-relaybox-mqtt: Python3 middleware for KMTronic USB 8 channel relay boxes to control the relays remotely with MQTT messages.
KMtronic or SDR-05V Cable
USB Relay Controller - Two Channels with clips for DIN mount rail