This is the  mini e cigarette Manual switch 401 battery
which is fitted with Mini e Cigarette models(BE401, M401)

Characteristics: 

    Diameter: 8.5mm
    Length:    75mm
    Weight:    15 g

    Connector screw: M7.0

  Content of battery :150 mah
  Nornal Working Voltage:3.6v-4.2v
  Full battery can keep for :about 250 mouthfuls
  Charge time:2-2.5hours