Identification of the authenticity of HLURU carbon steel Ethereal Drum?

At present, there are many tongue drum products claiming to be made of carbon steel, but the quality varies.
How to distinguish and avoid buying inferior products?
Ok, leave it to me
The first is the material.
There are two kinds of ethereal drums: one is made of carbon steel and the other is made of iron.
So, how do you tell?
The easiest and most scientific method is to use magnets, so there is no need to say more about the operation, right?
Iron: hold firmly
Carbon steel material: smooth rolling
The second is to listen to the tone.
Let's listen to the difference between carbon steel and iron.
The tone of carbon steel material is very pleasant and melodious...
There is a feeling of being in the bamboo forest, sitting cross-legged and sipping tea.
Iron is very bad
There is noise, the ending is very long
It made me feel dizzy.

The carbon steel ethereal drums on the market are high-end musical instruments, all priced at more than US$160.
Remind every fan of ethereal drums, you must identify them carefully before buying.
Don't buy cheap carbon steel ethereal drums.