Bolton Gate Company’s Sonaroll Roller Shutters combine several features/benefits into one high-quality attractive design. In addition to acting as a secure and weatherproof closure, the shutter offers a high degree of thermal and acoustic insulation. Extensively tested at the Department of Acoustics at Salford University, the door achieved a sound reduction of 27dB Rw, a considerably higher value than other roller shutters on the market. An augmented double curtain version is available which reduces sound transmission by 32dB. They are ideally suited to external openings where the acoustic envelope must be maintained such as power stations but are equally at home in internal applications where they act as a sound-break between two rooms e.g. exhibition halls, at a fraction of the price of other door types such as movable walls. They are available in large sizes (doors up to 10 metres high have been supplied) and are even available in a 25dB two-hour fire rated version.