The Walker's Rope Blue Tooth Hearing Enhancer features Sound Activated Compression with a High/Low compression mode. These lightweight and portable hearing enhancer is powered by Rechargeable Li-Ion battery and provides 15 continuous working hours. Also features High Gain Omni directional microphones for clear sound enhancement with HD speakers in the earbuds for wide range audio quality. Features 3 pairs of foam tips (S / M / L) included Rechargeable Lithium battery 12 inch USB charging cable included EVA Storage Case included NRR (Noise Reduction Rating) 29dB