Wrong "professional advice". Do not trust them.
They say on their website that they offer professional advice, but when you ask for the advice, they give you the wrong one leading you to buy the wrong product which they can't take back and won't admit they made a mistake. I told them I didn't understand about ventilation grids, and that's why I needed advice. I sent all the pictures, measurements and all information I imagined they could need to tell me which product was good for my situation, and they sent the link to the grids and they even wrote on the email which option of size I should choose. I the ordered the product and when I received I found out they told me to buy something way smaller than the measurements I had sent. They wouldn't admit they gave me the wrong advice saying it was my responsibility to check the measurements BUT I sent them saying it was 2.8cm thick and they told me to buy it 1.8cm thick (again, they sent me link and the option I should choose)! It would never fit, but again, should I be a professional to double-check that even telling them I wasn't??? Aren't they the professionals to give the correct advice and tell me what I should observe when buyng a product I could not return? Now I'm stuck with 3 ventilation grids that won't fit and I can't return because the shop is too proud to admit they made a mistake.