I have tested it. However, I was told the following via email:
pity that you have already disposed of the blades.
Normally, we request them so that quality assurance can examine them. Without a production code and the blades, I cannot refund you.
Therefore, I would like to make a suggestion to you for kindness. Please purchase a 4-pack of blades and send me the invoice. I will then gladly refund you up to 15 €, either via Paypal or bank account.