Neck speaker compatible with Bluetooth 4.0, with a 600mAh battery providing approximately 6 hours of playback. - Model Name: DTK-S420BK - Bluetooth Version: Bluetooth 4.0 - Output: 5W - Battery Capacity: 600mAh - Playback Time: Approximately 6 hours - Charging Time: Approximately 2 hours - Weight: Approximately 200g - Frequency Response: 20Hz-20kHz - Impedance: 4Ω I am selling this as I only had the chance to use it once. Thank you for looking.