Abstract: A lid to be used to dose the opening of a cooperative container providing a user with a spout that is selectively closed and opened to permit a user to draw the liquid inside the container and, if accidentally dropped, to avoid spillage and/or leakage of its contents. A slidable door is activated by a user to selectively block the liquid from coming out through the spout. A locking mechanism to keep the lid firmly and removably secured to the container includes a several latching members that extend perpendicularly from the periphery of the lid and engage with a corresponding number of openings formed in a peripheral locking member positioned adjacent to the rim of the container's opening.