These are used for the construction of water supply networks with a nominal pressure of 6 bar for water (calculated for a temperature of 20 °C), installed underground. The manufacturing method involves mechanical processing on machines for PE100 electrofusion couplers, with the electrofusion fitting’s resistance embedded in the material, corresponding to SDR 26 (ISO S12.5), in accordance with EN 12201-3:2011+A1:2012. 4 mm connectors. Welding is performed by authorized welders using appropriate equipment and adhering to the welding procedure.