Federal-Mogul Powertrain has developed a mechanical face seal for improved protection in extreme environmental conditions. The HSL solution features a unique elastomeric seal part to prevent dirt intrusion to sensitive components. A form of the square bore seal, the HSL is equipped with a protective dirt excluder lip to improve protection, reduce leakages, and extend service life. While conventional preloaded seal rings can cause particle gaps to form from the high pressures of heavy mud packing, leading to seal failure, HSL seals are designed to prevent this pressure and can be combined with various hard cast metals. The design is available in size ranges from 15 to 50 mm (0.6 to 2 in) and is suitable for mining, agriculture, construction equipment, and other large-scale machines.