All InvisiSound Performance Series drivers are constructed of Invarex, an advanced speaker cone material developed by DuPont laboratories. In the world of speakers, great sound depends largely on the quality of the materials used in the woofers and tweeters. The IS-5250 R Performer Series in-wall speaker system is specially designed for ambient applications. The durable and lightweight Invarex woofers produce a superior level of sonic performance. This system also features round, paintable grilles so you can customize the speakers to match your décor and recessed lighting system.