This is a rechargeable manual push buttong M402 battery for your M402 electronic cigarette.  The manual push button battery has a small push button located on the battery which you push to activate the battery.  This can often make for an easier inhale and more precise control of how long your battery is activated for. 

Average charge time is 4 hours after the initial charge of 8 hours. The M402 battery lasts for approximately 250 inhalations.  The M402 battery is 2 7/16 inches long or 62 mm.