Perimeter Technologies Invisible Fence R21 Replacement Collar - 10K

Your dog's containment system is only as reliable as the collar it runs on — don't let a worn-out receiver put your dog at risk.

This Perimeter Technologies replacement collar is fully compatible with Invisible Fence R21 systems using 10K frequency. It's a direct drop-in replacement — same fit, same signal, same reliable containment — so you can restore your existing system without replacing the whole fence. Waterproof and built for daily outdoor use, it keeps your dog safely contained without the cost of a full system upgrade.

If your current R21 collar is damaged, worn, or lost, this is the exact replacement you need to get your containment system back up and running fast.

• Compatible with Invisible Fence R21 systems — 10K frequency, direct replacement
• No new fence installation needed — works with your existing boundary wire
• Waterproof construction — built for daily outdoor use in all weather
• Rechargeable battery — no disposable batteries to replace
• Adjustable fit — fits a wide range of dog neck sizes

Specifications:

• Compatible system: Invisible Fence R21
• Frequency: 10K
• Waterproof: Yes
• Battery: Rechargeable
• Fits neck sizes: 6"–28"

Ideal For:

• R21 system owners replacing a worn or damaged collar
• Multi-dog households needing a second R21 receiver
• Anyone restoring an existing Invisible Fence system
• Dogs of all sizes with R21-compatible fences