Oh, I so thought these would be cool in the swimming pool or lake in the summer.  But when I got them, instructions say "do not immerse".  I suspect it is because the seal on the top might not be so good, and if one immerses them, water could get in the middle.  This will also make it difficult to wash -- don't put them in a sinful of sudsy water!     But, the do LOOK cool.

Pros: Cool red top looks good with red wine.
Cons: "Do Not Immerse" will limit functionality and ease of cleaning