These give off a lot of light and are a fun addition to bathtime. However, they don't last even close to the amount of time the package says-- each of ours lasted about a week or 2-3 hours of bath time (the box says 10 hours or 4 weeks). We made sure to take them out immediately so they weren't hanging around in water. At least one of them malfunctioned and wouldn't turn off after the bath, and so then it completely drained its power by the morning after the first use. Regardless, I would still repurchase. $2.50 for a week of fun baths is worth it to me.
It took me a while to figure these things out and buy them - and gosh they are even packaged in my hometown! But I grabbed some in my last order and they’re so fun. We’ve only used them in the bath but I can see lots of fun ways to use them in the future. I bought green!