Caution: color: we ship according to the color of the first picture, in the package: if the quantity is not stated in the description, we will ship the item according to the quantity and model number in the title. Suitable for surface keyboard surface keyboard surface go keyboards computer ipad keyboards| keyboards surface go product model and specification: 1. Bluetooth 3.0 Standard interface 2. Effective operating 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. Sleep 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. Key press force: 80 ± 10g 15. Key life: 5 million clicks 16. Working temperature: - 10 - + 55 degrees