Product review (4 stars): It works just fine...
Yup, it's a water filter! I've been purchasing the brand that came with my fridge (they were like $60 when I first started buying them 5 1/2 years ago)  but decided to give this much less expensive version a shot and it works just great. No leaks or odd tasting water. My other filters had almost a hard 'lock' to them so I knew they were in place along with the actual lock symbol and this did not. I was a bit hesitant that I had it tightened where is was supposed to go. Push up and twist and done.
After installation you have to run 5 gallons of water through it. If you've ever held that button down for 5 min... ugh.... good for you. I did a long 3 mind numbing min and decided that I'd do it in spurts for the next few days. I didn't get sick off of the ice cubes it made before I finished the whole 5 so I think I'm okay.
Great way to save a few dollars without noticing a difference. Now make it in the USA so I know it doesn't have scary stuff in it!