Yea, it looks like a useful tool to provide support while following the warnings:
Warning: Not suitable for children under 36 months Warning: Only to be used in water in which the child is within its depth and under adult supervision Warning: To be used under the direct supervision of an adult
I don't think it's a mistake that "under adult supervision" is said twice.
disclaimer: I'm not in any way a professional when it comes to water safety, so this is just a remark; not advice.