$23 Sonoff 4CH Pro 4-Channels WiFi & RF Switch Ships in a DIN Rail Enclosure - CNX Software
SONOFF 4CH Pro
Make a Cheapest DIY Sonoff 4CH : 17 Steps - Instructables
SONOFF 4CH Pro R3 Wi-Fi Smart Switch 4-Channel Din Rail Mounting Home Automation,Self-Locking/Interlock Control Home Appliances, RF/APP/Voice/LAN Control, Works with Alexa(1 Pack): Amazon.com: Tools & Home Improvement
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