Heavy Duty Nylon The strap on your dogs electric dog fence collar is an important factor in keeping your pet safe and contained within the boundaries of your underground dog fence system. Unfortunately, this is one part of the system that can become worn and shabby over time. Whether its the weather, or your dogs choose to chew on each others straps, the collars were designed to allow for periodic strap replacement. Invisible Fence Invisible Fence Micro Lite Invisible Fence R21 Invisible Fence R51 Invisible Fence Fence Mink eXtreme Dog Fence eXtreme Dog Fence Standard eXtreme Dog Fence Pro Grade eXtreme Dog Fence Max PetSafe UL-275V,M,D PetSafe UltraLight UL-250 Petsafe Inground Fence Receiver PUL-250 Petsafe Inground Fence Receiver C Wireless PUL-275 Petsafe Deluxe UltraLight PIF-275-19 Petsafe Wireless Receiver PRF-275-19 Petsafe Stubborn Dog Innotek Innotek SD-2225 Pet Guardian Pet Guardian PG-250 Other Brands Perimeter Technologies Dog Watch Contain A Pet Pet Stop