Perimeter Technologies Invisible Fence R21 Replacement Collar 7K - 1 Dog and Free Backup Collar Strap

INVISIBLE FENCE COMPATIBLE - This Collar Will Work with Invisible Fence Brand Inground Fences Prior to the 800 Series, Including ICT-700, ICT-725, ICT-750, ICT-775, ICT-150, ICT-250, ICT-100, ICT-75, ICT-50, AT-950 Indoor Transmitter, CT-4000 | NOT COMPATIBLE - These Collars Will NOT Work with Invisible Fence 800 Series Systems or Later Fence (Including the Titanium Series). . Will NOT work with Boundaries Plus Fence. Nor Will They Work With the Shields Indoor Avoidance Transmitters | FREQUENCY SELECTION - Most Invisible Fence Brand Underground Fence Systems Run on 7K, by Default. Systems that were Setup with Neighboring Fence Systems in Place May Run on 10K, to Avoid Interference | AMERICAN MANUFACTURED - This Collar is Manufactured U.S.A. With Imported Parts | Each Pet Fence Collar Order Comes with a Free eXtreme Dog Fence Backup Collar Strap