When the pump is activated, the product contained in the dosing chamber of the pump is subjected to pressure, which opens the valve and releases an accurate drop. Upon completion of the dosing process the system is sealed by the microbiological leak proof valve. This prevents the backflow of liquid. On release of the head base, the pump is reset to its initial position and a further aliquot of the product is drawn from the container into the dosing chamber. The vacuum within the container is compensated by the subsequent inflow of air, which passes through a special filter matrix. An oligodynamic effecting silver coil at the pump opening is a further microbiological safety component of the 3K-System.