Simple and does exactly what you expect - swings the bed.
You will need some man's power to install it (to do these 4 "clicks").
Very important is that you can change the position every day as you need, easily. Just push with you leg to close for the time you don't need it. And open back any time you need. So you can use swings during the day nap and keep the bed stable during the night.
Not expensive and very good quality. Looks also pretty safe. So absolutely recommend!

It matched with the Lionelo Sven Plus
https://www.skroutz.gr/s/17075158/Lionelo-Sven-Plus-2-in-1-Baby-Cradle-with-Allaxiera-Tirkouaz-125x65cm-1650603.html

Very good. It fits nicely in the park and has turned it into a swing. Every time the baby cries, it swings on its own. It was a bit difficult to fit it under the park, but I permanently have it on top.