«You definitely had this as a child!»?

If you were a child or teenager between the 1950s and 1970s, you may remember this strange object??
Every child in the 1950s-1970s will clearly remember this unique, strange object that looked like some kind of woodworking tool. But it turns out this object served a different purpose.
Here we present to you the roller skates of yesteryear
Before our familiar beautiful and smooth models, there were unusual heavy roller skates. These roller skates had a metal base and leather straps. The person would have to wear this over the user’s shoes.

Mysterious key
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.