the toilet water tank fittings are the core parts of the toilet, which are called "toilet heart" in the industry, and are mainly composed of water inlet valve, drain valve and button. Generally speaking, it can be divided into two categories: conjoined type and split type. One-piece fittings are used for one-piece toilets. Split fittings are used for split toilets. The inlet valve can be divided into side inlet, bottom inlet and back inlet. The drain valve can be divided into double-press type, hanging chain type and bucket type. The button part can be divided into side buttons, top buttons and front buttons.