Product review (3 stars): OEM 4396510; Pricing is against the consumer; Sizing mismatch for some needing 4396508
Yes these are OEM replacements that fit well into the refridgerator for which they're designed.  However, you have to be very careful as Whirlpool is advertising these as a replacement for both filter parts 4396508 and 4396510.

The filter I pulled out of my fridge was OEM and had model #4396510 listed on it.  It fit this perfectly.  However there are many complaints that people who need model 4396508 do not find this filter to fit; yet others find it does fit.  My best guess is that model 4396508 underwent an unpublished revision at some point, and so you're out of luck if you need 4396508 "original version" and not 4396508 "newer version".

Short story is, if you need 4396510 this is the one to buy, and if you need 4396508 then do some close photo comparison and make sure you compare your old vs. new filter once it arrives in case you need to return.  Also avoid poorly reviewed 3rd party sellers as there are many generics posing as OEM.

Final comment is that these are overpriced, this is to push you to buy them on a "discounted subscription" plan from Whirlpool directly so they can increase the reliability / stability of their cash flows.  Great for their business, bad for the consumer.