PetSafe SDF-R Sportdog Extra Collar For Inground Fence Best Halloween PetSafe SDF-R Sportdog Extra Collar For Inground Fence Halloween 2013 Sale Description Petsafe SDF-R Sportdog Extra Collar for Inground Fence is required when adding additional dogs the the SDF-100 in ground fence system. Extra collar receiver for the SDF-100 in ground fence system. Original Collar [...]