Perimeter Technologies Ultra Comfort Contact Pet Fencing System - No Wire PCC-200NW Chances are you heard about pet fencing from a friend or neighbor. The Perimeter Ultra Comfort Contact fencing you gives you the flexibility of changing the frequency. Perimeters exclusive Comfort Contacts cushion your pets neck with soft rubber, providing a lighter touch solution to hard steel contacts. Veterinarians prefer the softness of the Comfort Contacts to help avoid serious skin irritations.