This type of stuff would not be on their website as it is a niche product. You will need to go to the store. And my guess is that they will not have a large range of product. The other store to try would be a Sport XXX (Migros sports store).
If you are looking for something very specific, I would search and find a website then order the product (from either USA or UK for the English).
If you are looking for a very inexpensive foam mat (not pretty), they have some red ones (with the Interdiscount name on them) available from Interdiscount for about CHF 15 from memory. Will do the trick.
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