Hey, I would caution folks against using this type of glass lens base unless it's recessed into some other sort of receptacle that drops it down and flush with the top of that receptacle.
I used this kind of unprotected lens as a base in the past. I made one errant spin and the top shot off the side.
As it left the base, the body of the top dropped onto the edge of the glass lens as it fell off the side.
Because of the fast spin rate, the body of the top chattered and skittered against the unprotected, unpolished edge of the glass when the tip dropped off the edge.
I was left with a series of cuts, or gouges, on the bottom edge of the main body, covering half the bottom perimeter of my ruby tipped MKI.
And yes, this is a fantastic top otherwise.