Deep, foam-filled muffs provide excellent noise attenuation and hearing protection. Convenient, two-piece design enables use with most full-brim hardhats. Padded ear pieces enhance wearing comfort. Spring-design mounting bracket with telescopic leg simplifies installation and sizing. Dielectric. Material(s): Metal/Plastic; Ear Cushion Material: Foam; Noise Reduction Rate (NRR): 25; For Use With: Full-Brim Hard Hats.