Perimeter Technologies Is A Brand You Can Trust With Products That Are Loaded With Exclusive Features And Benefits Not Found In The Original. Perimeter Technologies' President Is The Same Person Who Founded Invisible Fence Brand Back In 1976!

Compare Perimeter Technologies With Your Current R21: Patented Comfort Contacts Cushion Your Dogs Neck In Soft Rubber Patented 3-Way, Omni-Directional Antenna Design Eliminates The Holes Found In Lesser Pet Fencing Systems Waterproof And Submersible Collar Receiver Design Progressive Stimulation Allows Your Dog To Choose The Fence Level That Is Right For Their Personality Ultra-Small And Light Weight Collar Design Is A Mere 1.1 Oz! Long Lasting Replaceable Lithium Ion Batteries Designed And Manufacured In The Usa With Imported Parts.

Limited Lifetime Warranty You Save! 100% Compatibility Guaranteed! This Replacement Collar Receiver For 700 Series Invisible Fence Systems Only And Will Not Work With 800 Series Or Later, Including New Titanium Series. The Perimeter Collar Is Not Compatible With Shields Indoor Avoidance Transmitters.

Fully Compatible With The Following Invisible Fence Brand Transmitters: Ict-700, Ict-725, Ict-750, Ict-775, Ict-150, Ict-250, Ict-100, Ict-75, Ict-50, At-950 Indoor Transmitter, Ct-4000 Please Indicate 7K Or 10K Frequency When Ordering. 7K Is The Most Common Frequency, The 10K Was Used In Installations Experiencing Frequency Conflicts With Neighboring Containment Systems.