YDDECW Thermostat Wire - 18/2 10FT Solid Copper 18AWG 2 Conductor Power Circuit Cable for Heating & air Conditioning Equipment, doorbells and Other Indoor/Outdoor Low Voltage Applications Use: Amazon.com: Tools & Home
Southwire 64169644 18/5 250' Brown Conductor Thermostat Wire, Solid Copper Class 2 Power-Limited Circuit Cable - Walmart.com