... for waterproof ,dustproof, shock absorption Specifications 1, executive standard: Bluetooth V2.0 2 Working distance: 10 meters 3, modulation system: FHSS 2 ... 25 days12, uninterrupted working time: 90 hours 13, charging time: 4-4.5 hours 14, Li-ion battery Capacity: Minimum 430MAH 15 ... , lithium battery life: 3 years 16, lithium battery Specifications: 4.5 * 24 * 47MM 17, key strength: 80 ± 10g 18, ...