Product parameters: * Speaker output: THD + N = 0.15% @ 2.0W SNR = 90db@2.0W * Headphone output: THD + N = 0.6% @ 32Ω SNR = 92 db @ 32Ω * Play time: about 10 to use the speaker about 20 hours (depending on volume size) using the headset for about 60 hours * Charging Time: USB Charging: 6 hours USB (5V/1A) AC adapter charge: 4 hours (optional) * FM radio :87 --- 108MHZ * Storage capacity: their memory 2G {optional memory (4G, 8G)} * Interface Transfer: USB 2.0 Full speed FAT16/FAT32 file system * File System: FAT16 / FAT32 * Music format: MP3 / WMA * Operating temperature: -18 ℃ ~ 80 ℃ * Dimensions: 88 x 38 x 38 mm * Weight: 138g