Viscio Tradingdiffusor Adapter, Stainless Steel, for Induction, 16 cm, 169626

I've been using this for 2 weeks and I'm very disappointed. The disc is already bronze colored and not flat anymore. I haven't immediately noticed that it was curved and I kept using it and this scratched the induction cooker. See images.I bought a product made in Italy that tought was better quality than the Chinese alternative on Amazon but it tuned out to be a very bad choice.