I thought I was buying the type that you fill the washer fluid reservoir with, but found that this "original" formula works great as well.  You wipe it on a clean windshield, and then buff out with a dry towel.  Rain water then beads up and rolls off the windshield, which improves your ability to see while driving through a storm.  It also seems to stay "on" for a while.  I highly recommend it.