Specifications: Executive standard: Bluetooth V3.0 Working distance: 10 meters Modulation system: FHSS 2.4G Transmittinf power: Class 2 Operating voltage: 3.0 – 5.0 Working current: < 4.0mA Standby current: ? 1mA Sleeping current: < 200?A Charging current: ?100mA Standby time: 60 days Uninterrupted working time: 30 hours Charging time: 4-4.5 hours Lithium polymer battery capacity: 330mA Lithium polymer battery life: 3 years Lithium polymer battery specifications: 40 x 16 x 50 mm Key strength: 80?10g Key life: 5 million strokes Operating temperature: -20C ~ +55C Celsius degrees Storage temperature: -40C ~ 70C Humidity: 20% – 50%