The Thunder series features a robust non deforming dielectric construction that withstands use and abuse, while protecting workers in electrical environments. Thunder also features Air Flow Control™ Technology which is standard on all earmuffs in the range. Dielectric construction with a plastic headband that does not conduct electricity. Suitable for virtually all workplaces, especially electrical and mining environments. Air Flow Control™ Technology for better, consistent attenuation, especially at low frequencies. Optimal protection for almost all noise frequency environments. Cap-mounted for use with wide range of popular hard hats. Earcups snap-lock in place during use and rotate back when not in use. Broad ear cushions allow plenty of room for outer ear, and improves wearing comfort. Snap in ear cushions makes cushion replacement quick and easy. Individual comfort setting remains fixed while wearing. Low profile earcup design. Complete with hard hat adapters in box - Part #’S 1000244, 1000245 And 1000249. SLC80 26db Class 5