The CX380 In Ear Canal Mini Speakers deliver massive sound despite their small size. The sweat proof coating wicks moisture away enhancing fit and durability. They have a noise isolating design that eliminates noise from the environment. The different ear adapters guarantee a custom fit. They are small, medium and large rubber cushions that are included along with a special carrying bag that eliminate tangles and fits in to any gym, workout or hand bag. The frequency response is 17 - 21,000 Hz, 16 ohm impedance, SPL is 113 dB. All Sennheiser Sports Series products carry a 2 year warranty.