The harsh environment series (HES) family of connection systems from Delphi Automotive is suitable for demanding applications including construction equipment and commercial, agricultural, and marine vehicles. The fully interchangeable system features improved sealing, retention, and current carrying capability. HES circular connection systems offer 24 shell-size circular connectors, pin, and sleeve terminals as well as 50- and 60-way header systems. The series prevents dirt, dust, and water from entering electrical connections, is compatible with existing systems, and is suitable for making connections in a firewall pass-through location, including engine compartments and high-density inline applications. A three-rib design improves performance, and recessed ribs enable a tight wire dress without compromising sealing properties. The high vibration system uses a fluorosilcone face seal suitable for engine mount applications; various configurations are offered.