It includes stipule stem, stipule box and stipule. The stipule is in direct contact with the nose and plays the role of supporting and stabilizing the mirror frame. Some cast plastic frames can have no stipule stem and stipule box, and the stipule is connected with the mirror ring.

The connection between the mirror ring and the mirror foot is generally curved.

The assembly position of the lens is fixed with metal wire, nylon wire and screws by means of grooves or holes, which affects the cutting of the lens and the shape of the glasses. Connect the left and right lens rings or directly connect with the lens. The bridge of the nose is either directly placed on the nose or supported on the nose through the stipules.