I understand that questions that ask for a shopping recommendation are off topic. However, after reading this answer, a question came up: is giving a shopping recommendation in response to such a question not allowed either?
I would only give an answer to a specific product if it
is a perfect fit for exactly what was asked
there are not many products of this type, so it is "rare"
and even then, I'd provide an explanation of why I am recommending this product, which is the critical part. You have to explain the rationale, and perhaps share research or experiences too.
I don't believe it's prohibited, but if we (the community we) provide answers to those questions that aren't allowed (for whatever reason that may be) then this only encourages more of these invalid questions to be asked in the future, which we really don't want.
There's also the danger of answers that suggest specific products, services, etc, being seen as spam.