The kit hence comprises base member 2 c arranged detachable directly to the surface of a desk, transfer means 31 c mounted horizontally on base member 2 c for traveling on wheels 32 c along first runway 21 c, joint member 5 c pivotably mounted at one end on the interior of first transfer means 31 c, support member 4 c including rotatable thread mechanism 6 c and transfer means 71 c, cradle member