The device, despite its size, is very useful and effective. It is suitable for beginner filmmakers who do not have a huge budget but want:
1) Better sound quality.
2) To listen (monitor) to the sound they are recording.
It takes a micro SD card, however, you do not need to have a card reader, you simply connect the zoom to the PC and you're good to go, the read and write times are satisfactory.
Personally, I used it alone with a 50 euro microphone from a well-known company and I can say that it does its job and more.
Negatives:
Plastic construction, so you should be careful with it. It would be good to carry it in the bag that comes with the box.

Very good overall, but I give it 4 stars for a few reasons.
1. It is made of plastic and seems like it could easily break if you're not careful.
2. The manual is small and almost useless. You have to download the electronic file. Imagine, it didn't mention anywhere that you can use up to a 32GB card. I had to look it up.
3. The box doesn't even come with a USB cable. For a machine that costs around 90 euros, I think it should come with a cable.
4. It takes a very long time to read the card and to delete a large file.

But it produces very clear sound and you can start recording with just 2 buttons.

Very good product with very good sound quality and many functions and options. The only negative is the build quality that gives you the feeling of cheap plastic

Excellent! Very good value for money. It is quite sensitive to "picking up sounds", so be careful not to shake it during use. For outdoor shooting, you will need a fur cover to prevent distortion from the wind.

Small and lightweight. Excellent sound quality! Many settings and format options. However, be careful, if you want to do external audio recording (not in a studio, etc.), you will definitely need a protective cover for the microphones. They are sensitive to the air and the result will disappoint you! Also, for those of you who do VLOGs or want it for camera audio recording, get a silicone base (shock mount) because it is so sensitive that it even captures vibrations from my gimbal motor (Feiyutech ak2000).

Check out my review to hear it live:
https://www.youtube.com/watch?v=6WzUt0XaaJ8&t=8s

See also the review I made in which the sound is actually with this specific microphone. https://www.youtube.com/watch?v=VjL0JNdaA3k

It is very lightweight, made entirely of plastic but it is one of the best sound recorders and microphones on the market which includes features that we only find in more expensive implementations. Easy to use, reliable and worth 100% of its money. A very good choice for portable recording with demands, podcasts, YouTube, etc.

Very good, when you first see it you think it's fake, there is no issue, it just needs attention during transportation (it doesn't have good plastics). However, it does its job perfectly, the sound is professional-like. For the money I got it (98 €) it is very good value for money