Noise attenuation
Enhanced noise attenuation on higher frequencies (the most harmful) and the shut-off valve offers 2 noise attenuation levels (high and very high):
-low protection in calm surroundings (4dB at 80dB noise).
-moderate attenuation for medium noise (24dB at 100dB).
-high attenuation for high noise (39dB at 120 dB).
Product details according to the manufacturer
MK 4 earplugs comply with CE standards for PPE in accordance with the EN 352-2 - 2002 standard.
Noise attenuation values tested according to standard EN 352-2: 2002 of directive 89/686/EEC (These values give the attenuation level for constant noise levels):
ALVIS MK4 closed NRR: 27 H: 28 M: 24 L: 24.
ALVIS Mk4 open SNR: 19 H: 22 M: 16 L: 11**.
2 positions
Open: the progressive filter reduces noise according to its loudness. Accurate and normal hearing in quiet conditions and protection in a noisy environment. Closed: occlusive and watertight ear plug.
Size
Available in two sizes M and L.
