It turns out that these metal roller skates had an interesting secret, which we will now unravel with you. Let’s look at the interesting key that was included with each pair of roller skates. And what was his goal?
With this key, people could change the tension or loosening of the skates. But if people lost their keys, it would be necessary to buy new skates.

Perhaps there are people among you who remember such unique and entertaining skates and the keys that were sold with them․ If you have such unique roller skates, you better keep it, especially if the key is still there! They will definitely become valuable items in the future.