SALE!! Advanced-Wire-Pet-Dog-Invisible-Fence-System-HT-023-Invisible Fence-Pet Fence-Dog Fence-Pet Boundary- Independent Play-Dog Play-Training Most reliable, cost-efficient pet fence containment systems available 1000 feet of wire and 20 flags included Adjustable nylon receiver collar; Longlife Battery included Safe and effective for dogs over 10 pounds No limit to the number of collars it can control