What's the name of the lion's head buckle on the gate?

Lionhead knocker is called "Lionhead knocker" or "Door King".

There are also some areas called "knockers", "knockers" and "door buckles". In traditional culture, the lion is a symbol of good luck, which is considered to ward off evil spirits and protect home safety, so it is often used as decorations such as door buckles and knockers in buildings.

The lion's head door buckle is usually made of copper, iron and other metals, with realistic modeling and fine carving. It is an important part of traditional architectural culture in China, and it is also one of the important features of ancient architecture in China.