In this instance, use some common sense and ignore it.....
You can try it yourself, its entire pages of wrong results, not one to skim over.
If you can't find what you're looking for on Amazon it's probably not the search engine's fault.
Of course this isn't the issue, I'm well versed in the other filter options they have to work around it, this is a principle of user experience and their primary filter not working.
Anyway, thought you may like to know there is more than meets the eye when it comes to search results. Like Prime exclusive products, they are overly controlling customers options which is going down a dark road.
If online sales are becoming the norm in society, replacing going into a shop and picking off a shelf, then what is the future going to look like under this current model? Should a supermarket start asking customers to subscribe to them or they dont get access to the entertainment isle?