The leather case is made of skin-friendly PU material, and the back is made of flexible TPU The TPU case adopts the honeycomb design, which can effectively heat dissipation With a pen slot for storage, you are not afraid of losing your pencils Comes with Bluetooth keyboard 3.0, upward compatible with 5.1 Bluetooth devices The Bluetooth keyboard adopts a high-speed chip, which can connect to Bluetooth devices in seconds It is charged with the Micro USB cable, and it can be freely carried and used when fully charged Specifications: Battery material: lithium-polymer battery Bluetooth: BT 3.0 (upward compatible with 3.0/4.0/5.0/5.1 Bluetooth devices) Effective distance: 10 meters Standby time: 100 days Working hours: not less than 100 hours Charging time: 2-3 hours Lithium battery capacity: 280mAh Lithium battery life: 2 years Button life: 3 million clicks Modulation method: GFSK Working voltage: 3.0-4.2V Working current: 14-17mA Standby current: <0.3mA Sleep current: <40uA Charging current: 100mA Charging method: Micro USB cable charging