Wireless Walkman with Bluetooth and quick connectivity via NFC one touch Built-in 4GB memory to store music – load up the Walkman with your favourite playlists Long battery life with 12 hours playback, 3 minutes quick charge for 1 hour playback Salt-water and extreme temperatures tolerant -5 degrees C to 45 degrees C Ambient sound mode turn back in to world around you Built in microphone for hands-free calling Lasting comfort with slim light weight approximately 32 grams Waterproof sports design