The Safariland® Pro Impulse® In-the-Ear Hearing Protection is a reusable, high-end earplug that offers users a Noise Reduction Rating (NRR) of 33dB. An enhanced contoured shape is easy to insert, and the proprietary material offers superior long-wearing comfort while patented IMPULSE™ Filter Technology automatically engages to protect the user's hearing from loud noises but allows normal ambient audio to pass through to carry on normal conversations. Plus, a key chain aluminum transport/storage case and 2 sizes of ear inserts (1 pair of filters) are included. No batteries required.