This wheel provides a very effective exercise for the core and abdominal area. In a short period of time, you will see results if you are consistent. Be careful during the exercise to avoid injuries to the waist area. There are many videos on the internet where experts highlight the correct way to use it for a safe and more efficient workout.
If you are concerned about the price compared to other similar ones that are 20-30€ cheaper, I must point out that this one is at least twice the size.
The built-in spring helps with the return from extension, but don't expect miracles. The handles are convenient and their construction is designed to prevent wrist fatigue.