Abstract: An apparatus for a robot arm of an industrial robot. A first module includes a first and a second member rotatable in relation to each other about a first axis of rotation. A second module includes a first and a second member rotatable in relation to each other about a second axis of rotation. The first member of the second module is attached to the second member of the first module. A third module includes a first and a second member rotatable in relation to each other about a third axis of rotation. The first member of the third module is attached to the second member of the second module. The second axis of rotation is substantially perpendicular to the first and the third axis of rotation. The second axis of rotation is offset from the first and the third axis of rotation when the first axis of rotation is substantially parallel to the third axis of rotation.