ZoningSupply.com - Zone Control - 24V AC Transformer (50VA)
120-240v 24VAC Transformer
Amazon.com: PWS-2440 24VAC 40VA Class II Power Supply AC Adapter UL 24V Transformer Plug with terminals : Electronics
24V AC Transformer
24VAC 40VA Plug in Transformer,Doorbell Transformer Compatible with All of Doorbell,Nest, Ecobee, Sensi and Honeywell Thermostat - - Amazon.com
N1 Common C Wire Adapter AC Transformer 24V 500mA Universal Compatible With WIFI Smart Thermostat and Doorbells. Nest, Ring, Honeywell, Ecobee, Sensi - White, New - Walmart.com
Replacement 24vac Transformer - 40VA Power | Woodland Direct