aFe Momentum HD Pro Dry S air intake systems are designed to give your Cummins, Power Stroke, or Duramax the air it demands. All Momentum HD systems are application-specific, dyno-tested, and tuned to provide maximum horsepower and torque. The Momentum HD Pro Dry S intakes are designed around massive Pro DRY S performance 360 degree, radial-flow air filters with three layers of progressive synthetic media providing 99.2 percent cumulative efficiency. Their unique, patent pending, air filter-to-housing interface allows for maximum filter size that increases the available air volume while simplifying the installation process. In addition, the air filters are wrapped in reinforced metal providing maximum strength to help prevent filter collapse.