We were given it as a gift, it didn't interest our little one at all (8 months old now), and we have it as a decoration...

It requires frequent battery replacement. My 5-month-old baby falls asleep more easily with the sounds of the doll. It is a bit expensive for what it offers.

It's not worth the money in any case.
It didn't help at all with the duration and quality of the baby's sleep (11 months old).

It has a very simple operation, basically you turn it on and it works for 12 hours unless you turn it off earlier. You can hear the sound of the heartbeat and breathing. My 9-month-old baby liked it a lot! Now, at 10 months, he hugs it and listens to the sound and calms down. It may be a bit pricey, but it is simple and well-made.

As construction, it is not worth the 50 euros in any case. It is a simple fabric doll that has a machine that makes heartbeats and breaths. For the money, the doll should be able to breathe and have a swollen belly. Since I received it 2 days ago, I don't have an opinion on whether the baby calms down when sleeping with the doll. If it does the job it promises, I will come back with a new review.