Suraielec 3 Way Wireless Light Switch, No Wiring, No WiFi, 100ft RF Range, Pre-Programmed, Expandable Wireless Wall Switch and Receiver Kit, Remote Control Light Fixture for Lamp, Ceiling Light, Fan - -
3-Way Wireless Light Switches With A Dimming Controller Kit – 1 Phase Dimming Controller, 2 Wireless Light Switches – RunLessWire
Belkin Official Support - How to install your Wemo WiFi Smart 3-Way Light Switch, WLS0403 in a 4-Way configuration