Cap-Mounted Ear Muff, NRR 21, Blk/Grn Price For: Each Item: Cap-Mounted Ear Muff Features: Universal Mounting Attachment, Stainless Steel Band, Earcup Pivot Points Dielectric: No Noise Reduction Rating (NRR): 21dB Standards: NRRa 21 dB. CSA Class B. Color: Black/Green Country of Origin (subject to change): Poland