Numpad - Universal - For Surfaces Keyboard Surface Keyboard Surface Go to Keyboard Computer iPad Keyboard | Keyboard (Surface Transfer) Highlights Universal For Surfaces Keyboard Surface Keyboard Surface Go to Keyboard Computer iPad Keyboard | Keyboard (Surface Transfer) Suitable for Surface Keyboard Surface Keyboard Surface Key Keyboards Cinkboards IPad Cinkboards | Keyboards (Surface Go) Product model and specification: 1. Bluetooth 3.0 standard interface 2. Effective working distance: 10m 3. Modulation mode: GFSK 4. Working voltage: 3.0-4.2V 5. Working current: less than 2.5mA 6. Standby current: less than 0.3mA 7. Night current: less than 40ua 8. Charging current: more than 200mA 9. Standby time: more than 100 days 10. Charging time : 2-3 hours 11. Lithium battery capacity: 350mAh / 550mAh (backlight) 12. Sustainable working hours: 35-100 hours 13. Lithium battery life: 3 years 14. press force key: 80 10g 15. Key life: 5 million clicks 16. Working temperature: - 10 - + 55 degree