Powershield Acoustic Sonata - Powershield AcousticPowershield Sonata is a high quality 28dB acoustic person… Encore - Powershield AcousticPowershield Encore is a high quality 37dB acoustic person… Quartet - Powershield AcousticPowershield Quartet is a very high performance 43dB acous… Symphony - Powershield AcousticPowershield Symphony is an extreme performance 45dB acous…