4 Digital Sound Processing Channels: General Crowds Nature & Power Boost 20-bit Audio Processor For Crisp Clear Sound 8-band Graphic Equalizer Nano-tech Water Repellent Coating Automatic Feedback Control 50db Of Hearing Enhancement Toggle Volume Control Sound-activated Compression (sac) Low-battery Tone Indicator Noise Reduction Rating: 29db #13 Battery Includes Carrying Pouch