EN45545 Compliant HDC Inserts TE Connectivity's (TE) EN45545 Compliant HDC Inserts comply with the European standard on flame retardancy for materials and products in railway rolling stock. The inserts for heavy-duty connectors provide a high level of flexibility when configuring railway connector systems. TE's HDC insert can be configured to hold anywhere from 1 to 216 pins and enable signal, data, and power to be transmitted via one single connector. The HDC inserts meet R22 and R23 requirements set on level HL3 and have an operating temperature of -40°C to 125°C.