This bundle consists of 2 items. Alternatively, you can get the expert-tier bundle, which includes both the Assassin’s water bottle and Schrödinger’s cat water bottle, 4 unique sleeves, and 2 engineering prints.Shrödinger's Cat Water Bottle: You must not use the Assassin’s water bottle to store poison, despite what the name might suggest. If you did, one side of the bottle would be deadly while the other would not. The fate of the person or animal drinking from the bottle would depend on the unobserved actions of the pourer. Which is reminiscent of some thought experiment involving a cat. This bottle incorporates a cat head design which is half white, and half black - half dead, and half alive. It also has the Steve Mould, Vsauce and Curiosity Box logos.  Each side can hold up to 450ml of liquid, with a combined volume of 900ml.  When demonstrating the magic trick we recommend you cover the bottle with a sleeve to hide the two compartments. Steve has unique stories for each sleeve: The P3M1 logo sleeve: There are only 17 different wallpapers. Which is to say, there are only 17 planar symmetry groups. My favorite is called the p3m1 group, which is almost what is shown on the logo sleeve. If all the logos were the same, it would be p3m1. But by sharing the logos between me and Michael, I have broken that symmetry. Which is what good artists do. I’m not sure what the symmetry group is now.