Overpromise and underachieve
First of all, it’s not dust-free. None of the tigerino crystals litters are dust-free (I tried them all).
And they don’t last 4 weeks either, not even close.
I have 3 cats and 4 litter boxes, so they should last 5 weeks. Instead, I have to change them no later than day 23-25.
I buy these only because within the “silica litters” category these are the cheapest.
If you have cats with allergies that need a dust-free litter, definitely this is not for you!