If you think "I will complete my purchase at this webshop, nice and handy" and it turns out later that you are missing all kinds of things, then you are not happy.
For example, we bought an extractor hood with this flex hose and thought it was a good fit. Not so, for connecting the hose you still need at least 2 hose clamps. Those hose clamps are not included here, and of course not with the extractor hood. Does CoolBlue sell them, no. Does a common hardware store sell them, no (not of this diameter anyway). So to the specialty store.
If you want to connect the flex hose to an existing hole, pay very close attention to what you need in terms of extra adapters, etc., perhaps also a roll of PVC tape to close everything airtight.
Look, CoolBlue just doesn't have everything for this job, so I can advertise where we received good help and where everything was for sale: it starts with a V and rhymes with Bentilatieshop.com
Gradients and such I can understand, very specialistic, but hose clamps are simply essential for connecting this product. You just have to buy it separately.