The use of glass increase the heightened sense of being connected. Glas sheets used, e.g. for tables reveal the secret of the construction underneath and demand careful design of what is above. A glass area, which iself is the main focus of attention, reveals the penultimate secret of a connection, which does not withdraw from communicating with the onlooker. By inserting a glass sheet into the frame from above, this dismountable shelf unit is being fixed.