Used for industrial and civil architecture roofing, basement, tunnel, tunnels, water supply and drainage pool, water pumping station, etc have waterproof impermeable concrete engineering requirements.

用于工业与民用建筑的屋面、地下室、隧道、巷道、给排水池、水泵站等有防水抗渗要求的混凝土工程。

youdao

Yes, I know that smartphones are not waterproof, and that jumping in the pool with one is generally a bad idea.

FORBES: What I Learned From Swimming With My SmartPhone

The Flex is indeed a waterproof product and can be worn in the shower or even the swimming pool, though we wouldn't advise you take it diving.

ENGADGET