Product review (5 stars): Replacement for Whirlpool 4396510 (and PUR W10186668) NSF 42 and NSF 53
Water filter replacement for 4396510. I used to buy the PUR W10186668 part that appears to be discontinued and this is close to the same price point and filtering properties.

The Everydrop product label says it is tested and certified for NSF 42 "Aesthetic Effects" (chlorine, taste, odor, and particulates) AND NSF 53 "Health Effects" (cysts, lead, mercury, ...) standards. NSF 53 is the difference between the under-$20 filters and then $30+ filters. Amazon's product listing and Whirlpool sites don't say NSF 53 specifically, but the paper packaging does. See photos.

The Everydrop seats perfectly in my KitchenAid circa 2002. As others have noted, the physical design changed slightly but this was not an issue for me. The shoulder of the canister is higher up. Also see my photo for side-by-side comparison with the PUR (left: Everydrop, right: PUR). First gallon flushed comes out virtually clear.

The cartridge is easy to push in and twist to install. To remove the old filter, I use twist the knob using the hand end of handles from a can opener or rubber gripped pliers.

The Everydrop 3/2016 product label says "Made in Taiwan" (vs. PUR W10186668 "Made in Mexico").