Found Chrome Plated Fur Saver Collars-3mm Medium for Bullmastiff
bullmastiff-breed.com offer Herm Sprenger Chrome Plated Fur Saver Collars – Three mm Medium Link for Bullmastiff
HS Fur savers collars are popular for medium and large breed breed with plush coats.
Oval shaped links do not pull the hair on the dog neck.
also collars Links can be clipped back on dead on various links which works best for growing puppies and showing Bullmastiff.
Size is measured end to end including the ring.
To have the correct size, measure your dog neck and add two-3”