SONODEC 25 TRD is a flexible acoustic duct consisting of a perforated aluminium inner duct, thermally insulated with a glass wool layer and protected by an aluminium-laminated outer jacket. An anti-migration barrier between the duct and insulation enhances mechanical strength and prevents the diffusion of insulation particles, while also reducing thermal bridging and moisture-related degradation. The duct ends are factory-taped to facilitate installation and connection.