I think it's more expensive, and I'm not sure it can absorb vapor (not liquid) It's fun that it has the same refractive index as water, so if you put clear one

I think it's more expensive, and I'm not sure it can absorb vapor (not liquid) It's fun that it has the same refractive index as water, so if you put clear ones in water they disappear. Then you ask someone to put their had in a bowl with them for a surprise.