Product review (1 stars): BEWARE! Two cartridge designs being sold under one EveryDrop model number.
Based on some of the reviews I was afraid to buy this off the web. Instead I went to the local Best Buy and was able to confirm what many are saying. This EveryDrop 5 filter is actually two different filters shipped in the same package and you won't know what you will get if you order it. There, at the store, on the same peg, were two different filters packaged identically. One, manufactured by Kemflo, matches the 4396508 filter I am replacing. (See photos) The other, manufactured by 3M, has a different, slightly rounded "shoulder" at the top of the cartridge where it narrows to the "stem" and has no notches in the shoulder. Another review here has a photo showing the two designs side by side.

On the packaging I looked at, both said they replaced 4396508, but I don't believe that, based on other reviews. Apparently the 3M mfg'd filter is compatible with 4396510, which seems to be a later design. My refrigerator is a Whirlpool GD5SHA side-by-side bought in 2003 with the filter in the grill below the doors. At $50 a pop, I didn't feel like experimenting to try the 3M mfg'd filter. The photos are actually of the filter I was replacing, showing the notches in the cartridge shoulder, but the packaging closeup is of the new EveryDrop package small print showing the manufacturer.

Good luck, everyone!