To be honest, I didn’t notice any differences with and without it, but perhaps there was less dust. Let it work, once bought. If I find something I'm more confident about, I'll change it.
Its pros:
At low speed, almost no noise, but the wheel rustles a little sometimes.
Cons:
After 4 months, it began to smell about - some slightly musty and sour smell, similar to wet dust plus sourness, although I washed the bath.See full review