Heavy Duty Pet Fence Wire and Flag Kit: 1,000 foot Pet Fence Wire & 100 Training Flag Kit. 1,000 feet of Heavy Duty, Solid Core Pet Fence Wire and 100 Pet Fence Flags. This is enough wire and flags to enclose 1 acre of yard. We highly recommend Heavy Duty Pet Fence wire in all areas where the wire may experience wear and tear such as rocky, sandy or shale ground types or very cold weather climates. This 1,000 foot reel of Heavy Duty Pet Fence Wire and 100 Flags can be used for any brand of underground pet fence.