NW Acoustical 645 is engineered to achieve unprecedented sound control up to an impressive unit STC 45. This system combines sleek acoustically separated aluminum framing and specialized gasketing with sound-enhanced glass to achieve optimal performance with the range of unit STC from 32 up to STC 45-all while allowing maximal transparency and natural daylight to floor interior spaces. Depending on the desired STC and glazing, maximum unit heightfrom 9ˈ 6″ (2900 mm) to 11ˈ 6″ (3500 mm) and maximum panel widths up to 3ˈ 3″ (1000 mm) are possible. NW Acoustical 645 with an STC 45 qualifies for Enhanced Acoustical Performance IEQc9 (LEED for Schools) and EQc9 (LEED for Interior Design and Construction).