Creative Labs ZEN Stone 1GB with built-in speaker. Player media type: flash-media, Total storage capacity: 1 GB. Audio formats supported: MP3, WMA. Frequency response: 20 - 20000 Hz, Signal-to-Noise Ratio (SNR): 90 dB, Total Harmonic Distortion (THD): 0.1 %. Continuous audio playback time: 20 h, Battery technology: Lithium-Ion (Li-Ion). Weight: 18.3 g