Howard Leight Thunder T2 Dark Green Over-The-Head HeadBand Noise Blocking Earmuffs with 28 dB NRR have dielectric construction and enhances worker safety by blocking noise in electrical environments. Plastic earmuffs feature a patented Air Flow Control? technology for optimal attenuation across all frequencies and a unique dual headBand for proper positioning and breathability. Earmuffs have headBand with a non-deforming outer construction to withstand rough treatment in the toughest workplaces while minimizing pressure on the head. They come with a uniform headBand pressure assuring a better comfort for all head sizes and support long-term wear. Earmuffs have snap-in ear cushions that make replacement fast and convenient and feature a quick click height adjustment.