TuneSound™System tube filters are needed for HYPƐAR™Sonic earplugs model Superior. You easily change yourself to which tube filters you want for each occasion. Smallest tube diameter [mm] in tube filter. The smaller tube diameter, the fuller bass. With increased tube diameter you hear more ambient sound. The safer choice if you e.g. are going out to exercise in city traffic. You also avoid taking out the earplugs if you need to have a short conversation. Filter choice: 0.15 mm; 0.20 mm; 0.25 mm; 0.35 mm; 0.4 mm; 0.5 mm