This is ring ferrite cow magnet, and also named Ceramic cow magnet. Ferrite cow magnet is popular with dairy farmers and veterinarians to help prevent Hardware Disease in their cattle. While grazing, cows eat everything from grass and dirt to nails, staples and bits of bailing wire (referred to as tramp iron).
1. Material: Y30 Ferrite magnets
2. Measure: 19Dia. X 78mm Long
3. Feature: 5 pieces ring ferrite magnets, 4 pieces/8 pieces washers and two stainless steel heads