Using Euro coins as weights (2004)

I'm using euro cents as weights in my weighted vest.

When I started doing this I didn't want to afford dedicated weights as it seemed like a waste of money, but I had many cents saved up from my childhood, which I started to use instead.

I have roughly 15kg in euro cents in my vest and I'm regularly talking walks with it.

To get one kilo you need 435 cents and it turns out that in Germany you can also "buy" coins "for free" at the "Bundesbank", that is, you can exchange actual money for weights without any fees. You give 4 euros and 35 cents and you get a kilo. Once you need the money back, you can also sell those coins back to them for free.

Could you explain more? I do not understand how you can buy coins for free by paying coins for “weights” (what are these weights? What are they made from?). Also, what is the use for this? To check of your coins are real? Calibrate your coin scale?

The coins are weights, the actual money is paper or electronic money.