I use it almost daily for kefir (it's plastic and therefore suitable). It's great and seems to have durability. I have never used the smallest size in the set; it is extremely small and therefore, I imagine, suitable for very specific cases (e.g., bottle necks or something like that).

I bought it to accompany my child's toy kitchen! I would give it 5 stars if it could also accompany mine accordingly, but due to the low quality of the sieve, I'm afraid it might melt if I pour boiling water. For its price, it's fine.