It draws in moisture internally and the electronic board burns out; apart from that, it is not the best thing from a safety standpoint to have moisture in its circuits, which operate at 220 volts mains voltage.

It seems to soften the dirt on the glasses more, since the water is heated by the vibration, rather than removing it or loosening it.

I used it twice for watches and glasses, the third time it stopped after 1 minute of use and had a strong smell of burnt plastic. I disassembled the device and half of the circuit board had melted inside. I knew it was from China, so I didn't expect much, but this is unacceptable from a device that worked for a total of 15 minutes. Be careful, I quickly realized it so that no harm would be done.

It broke on the 20th use, but I had put slightly hotter water in it and it probably overheated. With lukewarm regular water, it probably won't have any issues for a while. It definitely cleans something in watches that I used it on

Quite good for its price, I, who bought it mainly for cleaning my glasses, it did the job just as I wanted

For cleaning coins absolutely useless, check the comparison. Thank you. The item works quietly but unfortunately it is not effective. This device does not clean anything. See pictures. Thank you for nothing.

For 25 euros, it is decent for cleaning small items. Don't expect it to work well on very dirty or rusty objects.

I won't say it's perfect, amazing, and all that! It does its job decently with small objects, but for larger ones with more dirt (rusty screws), prefer something else.

Very good. I used it on various prescription glasses and it cleaned the hard-to-clean areas, such as the edges of the lenses that touch the frame and the nose pads. It also cleaned the bridge.
I didn't see much of a difference on keys and coins. I tried using a comb, but it didn't fit completely, although it cleaned half of it!
The drawbacks are that it makes noise, but I have it in the bathroom when no one is inside, and it is small, it doesn't fit combs, brushes, and generally anything larger than two prescription glasses together.
At this specific price of €30, it is very good.
On the other hand, it is difficult to find a larger ultrasonic cleaner at this price or even at double the price.

I didn't expect much, but it seems to work... mainly for vaporizers and watches...
Satisfied for now

Beautiful, convenient, helpful, and does its job perfectly. I use it for cleaning steamers and my glasses. It also states in the instructions that you can wash masks for anyone interested. Anyone interested can confidently purchase it as it is reliable for what it offers.