Product review (5 stars): The real fix for hollow Ice cubes
I had a problem where my ice machine was making hollow ice cubes and i couldn't figure out why.  I saw water going into the ice tray, and water was coming out of the water dispenser on my refrigerator. Replaced the icemaker on my Whirlpool just to find out this was indeed the part I needed.

The water pressure was not high enough to allow enough water to go into the ice trays for the right amount of time.  This part fixed that issue while simultaneously saving me a bunch of money when I returned the replacement ice machine that was not the problem.  Easy installation, takes about 10 minutes of your time.