If I could give this three and a half stars, I would. But I'll lean favorably and give it four. The stopper feels very secure after figuring out what it being sealed sounded like, from the audible "click" I hear when it's secure. The mixer in the lid gets its job done with little to no clumps remaining, which is the intent.
However, some folks may not even realize, but there are measuring bars on both sides of the shaker, between the logos to "see" how much water you've got in there. The issue comes in at how difficult these are to see, because it's frankly impossible to be sure how much water I've poured in with how transparent the markers are. I need to use a separate measuring cup to be sure I've put in the right amount of water for the mixture. Otherwise, the item does its job. Could be cheaper for how bare bones it is.