WQV 2.5/4 -1053860000 W Series Screwable Cross Connector. The ’W’ series screw clamp terminals are suitable for ’Top Hat’ DIN Rail and manufactured from nylon 6.6 which has a continuous temperature rating of 120°C (180°C short term). They are self-extinguishing to UL94V-0 and free from cadmium and halogen.