Thunder T1H Dielectric Helmet Earmuff (Note: Helmet not include) Dielectric construction Features patented Air Flow Control™ technology for optimal attenuation Quick-Click height adjustment remains fixed during wear Snap-in ear cushions make replacement quick and easy Noise reduction rating (NRR) 23 dB The Thunder® series features Bilsom® Technology’s patented Air Flow Control™ technology for optimal attenuation across all frequencies and snap-in ear cushions for easy maintenance.
