The 3M Tactical 500 has a targeted NRR of 26 dB for passive sound protection. Suppresses gunshot noise and amplifies low sounds using proprietary 3M technologies. Dynamic Supression Time measures the energy in gunshot noise and automatically sets suppression time for reduced echoes and increased comfort. Clear Voice Tracking Technology seeks voice amongst the noise to improve speech intelligibility and situational awareness. Bluetooth Wireless Technology to seamlessly sync to mobile devices. Engineered for optimal fit and comfort.