High Tech Pet UW-500 Ultra-Wire for Electronic Dog Fence Systems, 500-Feet Specially engineered for electronic dog fences with electrical and mechanical properties optimized for your dog containment application Suitable for use with any brand electronic fence,Solid copper core the wire is not standard wire. It includes an extra thick insulation that is heavier than what is used in standard wire. Extra high-strength insulation Resistant to sunlight, moisture, ground rot