Howard leight impact pro electronic earmuffs amplify low-level sounds and provide a noise reduction rating of 30.Designed with handgun shooters in mind, the impact pro actively listens and automatically shuts off amplification when harmful levels are reached.It connects to mp3 players, smart phones, and scanner radios.Included are 2 aaa batteries and a 3.5 audio input connection cord.Type: ElectronicColor: Black/GrayNrr: 30 dBQuantity: 1 PairStyle: Over the HeadBattery: AAA