Question Oh please find me the part number for this thing

This is kind of very off topic, hope to find the answer here before having to create an account on a electronics forum...
I just started messing around with arduinos, circuits and such, and I NEED to buy more of those things like the one in the pic

this one I extracted from a shock prank pen now I wanna know the part number/name so that I can learn about this thing and buy more of them, Im pretty sure that it is a step up transformer of some kind, it takes 3 lr41 batteries

Here I strapped the blue cover off looking for any numbers but could not find any... the only print on this thing is on the white circle soldered on the top and it has to marks 'lxm' and '6B'

Thanks in advance
Xperia Z [PAC 4.3] & Xperia Play [CM 10]
LiveView [Vanilla]
Nexus 7 16gb [C&C] & TF101 [4.3]
MK808 [Clock speed is locked at 1ghz...please take a look at this]
Ipod Touch 5g 32gb [6.1.2 Jailbroken]
Custom PC: 3570k@4.5Ghz & 7870@1150/1350
You developed a app and wants a videopreview for google play?? PM me and will be happy to do it!!
(if it is a ROM, Kernel or Mod, it has to be for one of my devices, will do them in portuguese with english subtitles or subtitles only)