It dates back to the 3rd century and was found in Bydgoszcz - Siernieczek. It is 5 cm long. It was cast in bronze. The clasp, also called fibula, was used to fasten clothes. It is made up of movable parts, working on the principle of a safety pin. The outer part, visible on the garment, is decorative. The needle-shaped, pointed element hides in the fabric. A comb-like ring is placed on the outer part, the so-called bail. The spring that tightens the needle is covered by a cap. The cap and bail are decorated with incisions imitating pearl ornamentation. Clasps are the most commonly found items of costume from the Roman influence period. Thanks to the variety and variability of such ornaments, it is possible to date an archaeological find with an accuracy of sometimes up to approximately 30 years.