Originally available in little blind packages from TOMY, these featured Gen1 Pokemon at the time - released in late 90s.
The set consisted of 4 types, Star shaped, Diamond shaped, and Hexagon shaped medals - The large circular medals were obtainable in a second print blind package along with the other shapes.
For the shaped ones, there are roughly ~50 of each I believe, for this large circular medals, there are 12 unique ones.
Onto the medal itself - front of medal has lovely features, Pocket Monsters wording, and a medium relief surface design, rear of medal has some Pokefacts on the specific character on the medal, and a Master Ball graphic!
The coins are metal and have a weighty feel in hand - just great