Mounts like these would be inserted along the length of a belt to add decorative elements. A great place to learn about belt mounts and how they were used can be found at the Rijksmuseum.
https://artsandculture.google.com/exhibit/medieval-chic-in-metal/HwKSigWK2MaHJA
Available as a set of 4.
Measurements: L = 2.2 cm, W = 2.2 cm
