Abstract: A top mount mechanism is located at the bottom of a mixer, faucet, or tap. The top mounting mechanism includes the following parts: a top mount flange (2), a clamp plate (3), and connecting accessories. The top mount flange (2) and clamp plate (3) are linked via the connecting accessories. The top mount flange is located at the bottom of a mixer, faucet, or tap, flexible hoses from a mixer, faucet, or tap go through the top mount flange (2) and clamp plate (3). Connecting accessories includes a clamp screw (4) and guide pins (5) at the sides, the clamp plate (3) can rotate through a spigot (7) on the guide pins (5), and it is connected to the clamp screw (4) via thread connection, the clamp plate (3) moves up and down sliding along the guide pins (5).