It has a similar composition system to silver brazing sheets and silver brazing rods, usually consisting of metals such as silver, copper, zinc and tin, with the only difference being its ring shape. It possesses the general properties of silver brazing filler metals, such as good wettability, filling ability and high joint strength. Its ring structure facilitates installation at the joint of welded parts, making it especially suitable for brazing circular or annular joints, and it can precisely control the welding position and the amount of brazing filler metal used. It is commonly used in fields like pipe connection, bearing installation and gear welding; for example, in air-conditioning refrigeration equipment, it is used for welding between copper pipes, and between copper pipes and joints.