The explanation that they give makes no sense at all.
The bit that is clear is false. It assumes that your property will rise by 5% a year for 50 years to rise in value from €100,000 to €1,092,000. You cannot design a financial product on a false assumption like that.
It seems to assume that interest rates will remain fixed at 5% for 50 years. Again, a false assumption.
It also assumes that the person will make repayments of €908 per month on their mortgage for 50 years. If someone can make repayments of €908 per month on their mortgage of €200,000, the bank is likely to be happy enough.
It seems that you need to pay a further €110 per week into some unspecified savings policy which will give you a guaranteed 2.5% a month for 50 years.
Why on earth would you invest at 2.5% , when you can invest at 5% by paying down your mortgage instead?