Hi people I'm buying something and its shipping and some how it shows up null and I don't know why. my tracking number is RB151258335CN

And I was wondering if you guys can help me out a bit and it is shipping by china air parcel and so I hope you guys can help my out I need my stuff by July 4 so I was wondering do you think it would come in before that Time and I live in the US so please can someone tell me why it says null and how long will it take