electronic lover

hi anyone I decided to make a high voltage stun gun for me.I think it is very interesting but I have questions about this project: 1-whats the role of j1 in schematic?Is that power button? 2-a picture of audio transformer or 2/220 1VA 3-whats U2 spark gap? more guidance and help for making pulse tranformer (u3 in schematic) ; a picture of it ; and a picture of ferrite stick. thanks alot.