Ping pong bats

Hello

I have seen all of your videos there great i hope you put more on. I have a donic Jan Ove Waldner level 900 attack bat. It has got a strange adjustable on the bottom and you could balance the bat, which is the best place to put the metal for a attacker. there is a plastic stick and there are three parts, the op the bottom or the middle.

Thanks for the help.