Southwire 500-ft 12-AWG Stranded White Copper Thhn Wire (By-the-roll) in the TFFN & THHN Wire department at Lowes.com
Homeowner Electrical Cable Basics | The Family Handyman
Southwire 500 ft. 12 Black Stranded CU THHN Wire 22964158 - The Home Depot
Amazon.com: AC/DC Wire and Supply 12 AWG Automotive High Temp GXL Wire Stranded Copper Wire 12 Colors with Legend Print (25 Feet Coil ea) Made in USA Z : Electronics