The Pro IMPULSE is a unique product offering superior noise-blocking (NRR of 33dB) performance in a reusable, high-end earplug. Its enhanced contoured shape is easy to insert and the proprietary material offers superior long-wearing comfort, delivering solid performance that you can depend on. The patented IMPULSE Filter Technology automatically engages to protect hearing but allows normal ambient audio to pass through. Great use for protection against single shot, explosions, automatic rifle fire, artillery, impulse & impact noise.