Special challenges in injection moulding cannot be overcome with classical mould temperature control. The solution is a variothermal control: High temperature during injection, cold temperature in the cooling phase. Together with two temperature control units Thermo-5, the Vario-5 forms a variothermal system according to the fluid-fluid technique. Alternatingly, it links either the hot or the cold unit to the same circuit. It is quite possible to use existing moulds if the temperature control channels are suitably arranged. Vario-5 provides easy and quiet operation. It supports the user in determining the optimum settings.