I have got the performance tip B originally its not of metal but i have got one which is same like it but it is full of metal . It provides great stamina , defense and also some times when i use it with my 85 spin track it provides high attack .
That means you have MB (Metal Ball).
actually its full of metal and looks same like the performance tip B
It's a fake part. In future, use Ask a Question, Get an Answer #2 for asking what something is, and beyblade random thoughts for... Well, random thoughts about beyblade.
I'd also suggest reading the "theflightyellz's guide to fakes and searching" for future reference. All three topics are in the same forum.
Also, generally there are already going to be topics for everything beyblade-related bar new parts and combinations (which both require testing to be made) or new and advanced concepts etc, so most new members have little need to make a beyblade-related topic for quite a long time. And, of course, if you haven't read your introductory PM from Kai-V, do that right away.
Moderators will be along to close the thread shortly, so there's no need to reply, but I wish you the very best in your time here.