These PetSafe style nylon replacement collars are made to fit PetSafe Brand receivers only. They feature a thick heavy duty nylon strap with many types to pick from. These Pet Safe collars are designed to fit any dog or cat. You just adjust the replacement collar to the length needed and cut off what is not needed. The outside two holes are used for all standard PetSafe receivers. The third center hole is only used to mount the PetSafe bark control collar receivers.