Is the Helo Strap waterproof?

Yes, it is. It has a waterproof certification of IP68, so you can wear it swimming in a pool or open water to a depth of 50m. 
The strap can be worn while washing hands, rain or swimming in shallow water, but does not support hot water showers, diving, surfing or deep submersion.

What if my Helo Strap/Card is not functioning?