This is a 1000 - foot Spool of our 16 gauge Premium Pet Containment Perimeter Wire. Our wire is more than 3X as thick as the 18 or 20 AWG wire you'll see elsewhere online. This is the very best wire on the market today for a durable, long-lasting dog fence installation, and it's compatible with ALL BRANDS. This wire conductor is made from bar annealed copper, and carries 19 copper strands for flexible durability. The polyethylene jacket is a full .45 mil thick, providing excellent physical protection as well as static and oxidation resistance. SPECIFICATIONS: Low density HMW - Polyethylene Tracer, suitable for direct burial. CONSTRUCTION: Bare per ASTM B3, B8 / Insulation per ANSI C8.35.