It is composed of an embedded peristaltic pump, which pumps air through a blue tube in a sealed bottle containing the polymeric solution. By means of a special cap, which guarantees perfect sealing and is equipped with 3 connectors, the solution is pumped in two tubes connected to the spinneret reservoir. This system allows optimal electrical isolation, and the special cap can be used for glass bottles with different volume (e.g. 250, 500 or 5000 mL).