With easy-to-read scale and large labeling field for easy marking in fired-on, highly durable ceramic ink. Complete system including DURAN Pressure plus laboratory bottle with 4-port screw cap (PP) , four screw connectors (black, M* thread) and silicone seals . Connection of different hose diameters; 1.6 mm and 3.2 mm as well as sterile pressure equalization sets. Unused ports can be sealed with silicone blanking seals.