Scott (the toilet paper folks) have come out with this new SmartFlush campaign. For a limited time, if you buy an 8 or 12 pack of Mega Rolls, you get one of these puppies for free. I'm torn on what I think about this. Displacing water in your tank is a great way to save water, but, you don't need anything special to do it. I've been doing it for years with a 1 liter water bottle. Easy. Fill it up, displace 1L of water. Save 1L of water every time you flush. Good for Scott for raising awareness, but it seems a little wasteful to manufacture these things.