The Empty Twin Pump Marker 1.5 - 4 mm Starter Kit with 2 empty markers including pre-assembled Refill Extension in a sustainable cardboard packaging.Double pump action! Everyone has dreamt of a twin and this one has it all! Two different tips (1.5 mm and 4 mm) make this acrylic classic ready. Moreover, the pump marker is equipped with the Refill Extension B – so the marker can be refilled cleanly. It also ensures a larger filling quantity.