Change default sub-level list symbol

Question

I want to change the default symbol for the sub level of itemization list after pressing TAB. Specifically, I start with a raw list.

I then highlight three bottom bullets and click TAB. I then obtain

Thanks to the (hidden) default feature, a new sub-list is created with hyphen used for each item. However, I do not have preference for that. In addition, the hyphen before $\mu$ makes a confusion that it is a negation. That is why I have to manually change the sub-list into what I prefer

My question is: How I can change so that each time I press TAB, I obtain the last figure immediately?

I am asking this because I am lazy to use mouse, so I prefer after highlighting and pressing TAB a magic appears :).