Very cute and make an adorable gift for geeky friends, but they can only be rinsed, not submerged in water, which means they can't be properly cleaned. I didn't notice this until I read the fine print on the package. As a mom of a sticky-fingered-and-faced baby, I know these are never going to be used, regardless of what the recipients kindly say. Despite the cute factor, I wouldn't buy again.