A handle for door or window having a movable sash , comprising: - a grip having a gripping portion and a base portion or neck facing, in use, a part of the outer profile or wing of the movable sash ; the grip being rotatable about a first axis (X3); - a shaft protruding from the grip and passing, in use, through the outer wing of the movable sash ; - a kinematic unit positioned, in use, in the proximity of a longitudinal channel inside the profile of the sash in which at least one control rod slides and is coupled, in use, to the protruding shaft ; the kinematic unit being connected to at least one control rod designed for converting the rotational movement of the grip into a translational movement of the rod , in both directions; the kinematic unit comprising: - a first and a second gear wheel , different to each other, placed side by side and in contact with each other and having a seat positioned, in use, coaxial with each other and engaged simultaneously by the shaft ; - at least one rack having two separate meshing tracks placed side by side and engaged by a corresponding gear wheel ; the rack being formed on a rod-shaped body positioned, in use, parallel to a free upper surface of the channel and provided with means for coupling with the at least one control rod , characterised in that : the toothed surfaces of each track of the rack are incised on the rod-shaped body in such a way as to define corresponding tracks with hollow meshing surfaces , recessed relative to a reference plane (P22) of the rod-shaped body , for the teeth of the first and second gear wheel , and wherein each track (21a 21b) is different and separated by a central longitudinal rib . - a grip having a gripping portion and a base portion or neck facing, in use, a part of the outer profile or wing of the movable sash ; the grip being rotatable about a first axis (X3); - a shaft protruding from the grip and passing, in use, through the outer wing of the movable sash ; - a kinematic unit positioned, in use, in the proximity of a longitudinal channel inside the profile of the sash in which at least one control rod slides and is coupled, in use, to the protruding shaft ; the kinematic unit being connected to at least one control rod designed for converting the rotational movement of the grip into a translational movement of the rod , in both directions; the kinematic unit comprising: - a first and a second gear wheel , different to each other, placed side by side and in contact with each other and having a seat positioned, in use, coaxial with each other and engaged simultaneously by the shaft ; - at least one rack having two separate meshing tracks placed side by side and engaged by a corresponding gear wheel ; the rack being formed on a rod-shaped body positioned, in use, parallel to a free upper surface of the channel and provided with means for coupling with the at least one control rod , characterised in that : the toothed surfaces of each track of the rack are incised on the rod-shaped body in such a way as to define corresponding tracks with hollow meshing surfaces , recessed relative to a reference plane (P22) of the rod-shaped body , for the teeth of the first and second gear wheel , and wherein each track (21a 21b) is different and separated by a central longitudinal rib . - a first and a second gear wheel , different to each other, placed side by side and in contact with each other and having a seat positioned, in use, coaxial with each other and engaged simultaneously by the shaft ; - at least one rack having two separate meshing tracks placed side by side and engaged by a corresponding gear wheel ; the rack being formed on a rod-shaped body positioned, in use, parallel to a free upper surface of the channel and provided with means for coupling with the at least one control rod , <EOS>