You don't need this, but it's visually attractive and you can combine it in all sorts of ways.
I love sound gadgets, so I got this.
With every cymbal type this is stacked with, you'll get another sound, but it will always be trashy or sizzling.
I found it especially interesting with my 16" Istanbul China.
It doesn't pop up because of the China shape it lies on, and I had the choice between a sustained tone or a short burst.
That is achieved by playing on the edge of the China, or hitting the spiral stacker lying on top directly.
Which also gives you clearly different sounds as well.
And I'm not even finished experimenting.
On it's own, hanging down, it's about using your imagination how to blend this into your play. (and where to place it in your kit)
Because when used solo, you're going to need at least 50 cm to let it dangle free.
It isn't loud, so it will never be a power lead crash, it doesn't cut through.
It's more like a sizzle-crash and sound filler.
Excellent for the slower tempo songs, soft grooves, jazzy stuff and acoustic play.
But it's best purpose is to stack it.
This will be very interesting for recordings too.