Capacity: 750mAh Battery Type: Li-Polymer Voltage: 3.7V Model numbers fit to: Sony NWZ-A720, NWZ-A726, NWZ-A728, NWZ-820, NWZ-A726, NWZ-A826, NWZ-A828, NWZ-A829, NWZ-A729BLK, NWZ-S738, NWZ-S738FBNC Compatible battery part numbers: 1-756-702-11, 1-756-702-12, LIS1374HNPA, 8315A32402, 8917A44167 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'.