"Flashlights Lighting or other device that needs 3.7V power Building portable power device needing high energy density and low weight & More! Type: Cylindrical Cells 3.7V 1200mAh Chemistry:Lithium ion Dimensions:18(Dia)*65(H)mm Nominal Capacity:1200mah Nominal Voltage:3.7V Weight:30g Max Charge Voltage:4.2V Discharge cut-off voltage3.0V Life cycle:?1500 Portable electronic products *Mp3&Mp4. Digital products .Laptops. Electric toys. Electric modern aircraft. Camera. Remote control CD players.Video cameras.Recording pens.Wireless mouses. Cordless Phones&walkie talkies *Telephone. Wireless microphone .Communication equipment . Emergency lighting &Led Lighting *Flashlight .Led lights .Emergency lighting . miner's lights.solar power lights . Power tool*Cordless power tools.Charging type electric tools.Vacuum cleaners.Sweeping machine .Model airplanes.Remote control models.Inflatable pumps. Electric bicycles*Electric bike .Electric Motorcycle "no of units in package 4