When it comes to selecting an earmuff, comfort reigns supreme with workers. That's why the Thunder series earmuff is designed with all-day comfort in mind. Headband earmuffs feature a unique dual-headband for better positioning and breathability, and non-deforming outer headband that minimizes pressure on the head. Plus, its dielectric construction withstands use and abuse, while protecting workers in electrical environments. High-attenuating cap-mounted ear muff that fits most slotted hard hats - no tools required. NRR 27dB. Tested to ANSI S3.19-1974 standard. Sold by the each.