Shelly
How to wire Shelly 2.5 in circuit with 3 switches? - Shelly 2.5 - Offizielles technisches Shelly Support Forum (DACH)
How to hook up Shelly 2.5 to a 3 way switch? : r/homeautomation
Buy Shelly 2.5 - Double Relay Switch and Roller Botland - Robotic Shop
Shelly support group (English Version), I just purchased my first Shelly 2.5 device
Transform any device with Shelly and Home Assistant: A step by step guide for 3-WAY circuits
Automate Two Light Switches (Home) w/ One Device - SkylerH Automation
Shelly Plus 2PM - 2-channel Switch/Roller Shutter - Android/iOS application Botland - Robotic Shop
Factory-resetting Fibaro FGS 222 relay switches - Home Automation - openHAB Community