Here are the spare parts for inner acoustics of S4R, and S4R 1.1 model.
2x body back cover
2x acoustic foam
2x SAATI flow resisting meshes
2x acoustics cylinders
IMPORTANT: We advise that all the major parts replacements and modifications are performed by our certified engineers in our facilities in Slovenia, Europe. With any visible DIY done modifications, repairs, upgrades within the 5-year warranty period, the warranty is voided due to inability to properly inspect the source of the potential damage done by the user.