For Microsoft Surface Pro 4 / 5 / 6 / 7 Keyboard Magnetic Rechargeable Bluetooth-compatible Keyboard (Without Backlit) The keyboard can be connected with leather cover (not included) by magnetic adsorption, and change into the working mode of laptop Bluetooth-compatible 3.0 wireless connection, fast response without delay, more power saving Built-in 420mAh battery, can be recharged via attached cable Simple design, thin and portable, easy to carry Specifications: Dimension: 281 x 185 x 6.5 mm Weight: 280±5g Bluetooth-compatible solution: BT3.0 Valid distance: >=10 meter Working voltage: 3.7V Standby time: 180 dadys  Charging time: 2.5 hours  Battery capacity: 420mAh  Battery lifespan: 3 years  Working temperature: -10 to +55℃