3M EAR 320-1000 headphone type earplugs noise reduction anti-noise earplugs industrial noise reduction earplugs

3M EAR 320-1000 earphone earplugs
Model: 320-1000
NRR: 28DB
patented EAR FORM foam material, soft, safe and non-irritating
earplug shaft rotating design, better tightness,
high visibility, headband,
earplug head replaceable
packaging: 10
pairs /box, 10 boxes/carton = 100 pairs NRR: Single value noise reduction value tested according to the American standard ANSI S3.19-1974.
SNR: Single value noise reduction value tested in accordance with the international standard ISO 4969-2