Zongshen ZS250GS 06

Hey guys I just bought a Zongshen ZS250GS and i also got a scorpion aftermarket exhaust to put on. the only thing is I know that I have to rejet the carburator but I have no clue where to buy a rejetting package or what size should I get, I don't even know what size is the stock main jet... Can somebody help me pliiiizzzz
Thanks