A mechanical system for non-linear conversion of a rotational movement into a linear movement comprising: a fixed rod connectable at a first end to a cartridge assembly of a faucet having at least one operating lever for providing at least one separable movement control to said cartridge assembly; a handle rotatable in a first rotational movement about a first axis located at a second end of said fixed rod between a first angle of rotation associated with the closed position of said faucet and a second angle of rotation associated with the fully opened position of said faucet, adapted to provide a second movement control by means of rotating said fixed rod about its longitudinal axis and a first movement control by rotating said handle about said first axis; a rocker element rotatable about a second axis located at said first end of said fixed rod, said rocker element comprising a jag at its circumference adapted to linearly move a moveable plate of said cartridge; a movable rod pivotally connected at a first end to a third axis located at said handle remotely from said first axis and pivotally connected at its second end to said rocker element at a fourth axis located remotely from said second axis; characterized in that said at least one separable movement control is a rotational movement of said handle about an axis perpendicular to said longitudinal axis of said fixed rod, and a second movement control by means of a rotational movement about the longitudinal axis of said fixed rod provided by a second rotational movement of said handle and wherein said first rotational movement control and said second rotational movement control are mutually independent of each other; and the tangential movement of said jag in a direction perpendicular to said longitudinal axis is nonlinearly relative to the rotation of said handle about said first axis where said tangential movement associated with a position of said handle close to the closed position is smaller than said tangential movement associated with a position of said handle close to the fully opened position. a fixed rod connectable at a first end to a cartridge assembly of a faucet having at least one operating lever for providing at least one separable movement control to said cartridge assembly; a handle rotatable in a first rotational movement about a first axis located at a second end of said fixed rod between a first angle of rotation associated with the closed position of said faucet and a second angle of rotation associated with the fully opened position of said faucet, adapted to provide a second movement control by means of rotating said fixed rod about its longitudinal axis and a first movement control by rotating said handle about said first axis; a rocker element rotatable about a second axis located at said first end of said fixed rod, said rocker element comprising a jag at its circumference adapted to linearly move a moveable plate of said cartridge; a movable rod pivotally connected at a first end to a third axis located at said handle remotely from said first axis and pivotally connected at its second end to said rocker element at a fourth axis located remotely from said second axis; characterized in that said at least one separable movement control is a rotational movement of said handle about an axis perpendicular to said longitudinal axis of said fixed rod, and a second movement control by means of a rotational movement about the longitudinal axis of said fixed rod provided by a second rotational movement of said handle and wherein said first rotational movement control and said second rotational movement control are mutually independent of each other; and the tangential movement of said jag in a direction perpendicular to said longitudinal axis is nonlinearly relative to the rotation of said handle about said first axis where said tangential movement associated with a position of said handle close to the closed position is smaller than said tangential movement associated with a position of said handle close to the fully opened position.