There is a black circle in the cold water pipe of Mohn bathroom.

The sealing ring is the original fitting of Moen bathroom, which is used to prevent the cold water pipe from leaking and the invasion of dust, water and other external residues. Therefore, the cold water pipe of Moen bathroom has a black ring as the sealing ring.

Moen, an American kitchen and bathroom brand, is widely used in middle and high-grade houses, high-grade hotels, villas, apartments, business offices and various public buildings.