An adjustment instrument for an exterior mirror unit for a vehicle comprising - a housing which is pivotable with respect to a base between a park position, a drive position and a fold-over position, and which is provided with a first series of cams; - an electrical drive unit which is received in the housing for electrically driving the pivoting of the housing; - a clutch gear comprising a drive ring and a clutch ring, wherein - the drive ring is under spring force and is arranged for cooperation with the electrical drive unit; and - the clutch ring is provided on the drive ring, and is arranged for transmitting the spring force; - a lock ring which is located on the housing and which is set up non-rotatably with respect to the base and which in the drive position receives spring force via the clutch ring and which outside the drive position is free of spring force during electrical adjustment to the park position; - a cam ring which is provided on the base, and which in the drive position is free of spring force and which outside the drive position receives spring force via the clutch ring; - a second series of cams which are set up non-rotatably with respect to the cam ring and arranged for cooperation with the first series of cams; wherein the pattern of the series of cams (10,11) is such that the cams (10,11) can interlock only in one or in a few pivoted positions such that - the series of cams interlock in the drive position and by the spring force can be pressed onto each other to define the drive position, and outside the drive position sit on each other and can slide over each other, and wherein - the clutch ring from the drive position towards the park position, is free to pivot with respect to the cam ring, characterized in that for the purpose of electrically driven pivoting of the housing from the drive position in the direction of the park position, while the series of cams (10,11) interlock in the drive position, the clutch gear first moves over running surfaces of the cam ring until abutting against cam ring cams of the cam ring so that the clutch ring has a limited free stroke with respect to the housing and the cam ring between a first angular position in which the clutch ring transmits the spring force onto the housing and cams (10,11) are pressed onto each other by the spring force, and a second angular position in which the clutch ring leaves the housing free and transmits the spring force onto the cam ring, so that the cams are not pressed onto each other by the spring force. - a housing which is pivotable with respect to a base between a park position, a drive position and a fold-over position, and which is provided with a first series of cams; - an electrical drive unit which is received in the housing for electrically driving the pivoting of the housing; - a clutch gear comprising a drive ring and a clutch ring, wherein - the drive ring is under spring force and is arranged for cooperation with the electrical drive unit; and - the clutch ring is provided on the drive ring, and is arranged for transmitting the spring force; - a lock ring which is located on the housing and which is set up non-rotatably with respect to the base and which in the drive position receives spring force via the clutch ring and which outside the drive position is free of spring force during electrical adjustment to the park position; - a cam ring which is provided on the base, and which in the drive position is free of spring force and which outside the drive position receives spring force via the clutch ring; - a second series of cams which are set up non-rotatably with respect to the cam ring and arranged for cooperation with the first series of cams; wherein the pattern of the series of cams (10,11) is such that the cams (10,11) can interlock only in one or in a few pivoted positions such that - the series of cams interlock in the drive position and by the spring force can be pressed onto each other to define the drive position, and outside the drive position sit on each other and can slide over each other, and wherein - the clutch ring from the drive position towards the park position, is free to pivot with respect to the cam ring, characterized in that for the purpose of electrically driven pivoting of the housing from the drive position in the direction of the park position, while the series of cams (10,11) interlock in the drive position, the clutch gear first moves over running surfaces of the cam ring until abutting against cam ring cams of the cam ring so that the clutch ring has a limited free stroke with respect to the housing and the cam ring between a first angular position in which the clutch ring transmits the spring force onto the housing and cams (10,11) are pressed onto each other by the spring force, and a second angular position in which the clutch ring leaves the housing free and transmits the spring force onto the cam ring, so that the cams are not pressed onto each other by the spring force.