This is the standard, cast Alnico cow magnets that has been the favorite of dairymen and veterinarians for nearly 30 years.
Cow mangets can prevent Hardware Disease in the cow. While grazing, cows eat everything from grass and dirt to nails, staples and bits of bailing wire (referred to as tramp iron)Rigid Hips Cow Magnets wont be coming soon, unfortunately...
My brother and I used to find those in fields growing up. We ruined one at least one television with them.
SvaraRadera