SPECIFICATIONS AND EQUIPMENT CLASS a). Power supply: Input voltage: 220VAC+10% Output voltage: 4.2VDC+/-0.1 Output current: 600+/-50 MA b) Internal power supply Lithium battery: 3.7 v Saturated electricity measures 700mAh Charging time: about 2.5 hours c). Equipment class: Class A (Medical Appliance Classification Catalog) d). Protection from ingress of liquids: None e). Lamp: 3.6V AC, 3W f). Output wavelength range: 420-480nm (nanometers) g). Feature size: ¢ 20*198mm h). Net weight: about 105g i). guarantee time : one year