Born from our original Noise S.T.O.P. Climate Seal™ Thermal Series Windows, the Noise S.T.O.P.™ Acoustic Series Window Insert specifically focuses on sound abatement across all frequency levels with exceptional results while maintaining its discreet look and superior thermal properties. While the Noise S.T.O.P. Climate Seal™ Thermal Series abates sound by up to 60% from pre-existing levels, the Acoustic Series boasts up to an 80% sound reduction from pre-existing levels! Our Acoustic Series Model has a peak Sound Transmission Classification or “STC” of 49. This matches or exceeds the performance of other competitive products and does so at a significantly reduced cost and aesthetic impact to your existing window cavity.