I believe the Tru Channel window is the best storm window on the Market. Storm windows are generally rated by using an air infiltration ratio. The industry average is right around .61 CFM (Cubic Feet Per Minute). The Tru Channel is rated at .04 CFM. Here are some highlights:
Approved for airport sound abatement programs.
Fully weatherstripped sashes and masterframe
Multi-chambered, heavy duty master frame
Independent meeting rail, interlocked and weatherstripped
Baked on Enamel Finish (10 year warranty)
Available in White, Bronze, Almond and Black (10% more for Black.)