- Your Steel HR can withstand a pressure similar to that of a 50 m (165 ft) depth. You can, therefore, use it when dishwashing, splashing or swimming. however, it can't be used for diving or snorkeling.
- Do not press the button of your Steel HR when it is under water.
- Avoid long exposure to salt water. Make sure you rinse your watch with fresh water after spending time swimming in salted water.
- Avoid exposure to any chemical products such as solvents, detergents, perfumes or cosmetics. They may damage the wristband, the casing of the watch, or the HR sensor.
- Avoid extreme atmospheres (e.g., saunas or steam rooms)
- The aging of the materials may affect the waterproofness of the watch. Water resistance cannot be permanently guaranteed.
https://support.withings.com/hc/en-us/sections/4411850426129-Steel-HR-Steel-HR-Sport
https://support.withings.com/hc/en-us/sections/205815308-FAQ