Capacity: 350mAh Battery Type: Li-Polymer Voltage: 3.7V Model numbers fit to: Sony BT21, BT22, DR-BT21, DR-BT22, DR-BT21G, DR-BT21IK, DR-BT21GB Compatible battery part numbers: BP-HP300A, 65358-01, 64399-01, 64327-01, PLN-6439901, ED-PLN-6439901, 6535801 RoHS approved for toxic free. CE and ISO9001 Certified for Quality Assurance. Search Tip: Press Ctrl and F keys to prompt a search dialogue box, then type in your device's model number and click 'Find Next'.