Lieber White Plastic 3 Gang Light Switch with 1 dimmer (2x 2 Way Switch & 250w Trailing Dimmer) - Elesi
How-to: Replace 3-Way Switches With Smart Dimmable Switches - YouTube
Brilliant Home Control (3-switch control)
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TOPGREENER In Wall Dimmer Switch Single-Pole/3-Way LED Decorator Light Dimmer with Wall Plate, White (3-Pack) in the Light Dimmers department at Lowes.com