The worst thing ever! This new model with the replacement filters is unacceptable. The previous one, where you changed the entire nozzle, was excellent and I used it for my first two babies. Now, with the third one, I had to buy this one and I threw it away in less than a week. Firstly, the filter is so thin that it doesn't retain the mucus when you suck it out, and it falls back into the nose. Especially when I used serum before, I had to suck so hard that my lungs almost came out in order to prevent them from falling back into the nostril, and with the strong suction, they ended up almost in my mouth because the filter is not stable. Also, no matter how skillfully I tried to remove the filter, there is no way the mucus doesn't spill onto my hands. So I had to either let the baby cry or have another person with me to wash my hands and the aspirator every time. I don't understand why the company changed a successful product into a completely failed one. My review is for use on a sick baby full of mucus that needs to be removed 4-5 times a day. I don't use the aspirator preventively every now and then to see if there is any mucus. After my experience, I recommend an aspirator with replaceable nozzles and not filters. Filters are not suitable for "heavy" use.