Its nice to have a backup collar strap on hand for your PetSafe In-Ground and Wireless Fence Receiver Collars. Both the 3/4 in and 1 in sizes have 2 holes that will fit several pet fence or remote training receivers that only have 2 contact points. These straps are not compatible with bark control receivers. To remove the receiver unit from your pets old collar, simply unscrew the contact points and take it off the old collar strap. Then, secure it to the replacement collar strap. Your pet deserves the best. Trust PetSafe to keep your pet healthy, safe and happy.