https://www.swim.com/smartswimwear/

Description:

And evolutionary. The next phase of swim wearables. We are working on a smart swim tracker that is integrated directly into your swimwear. Just swim and let your suit do the tracking. Add the swim tracker to almost any athletic swimwear at SwimOutlet.com. Never worry about charging, your tracker will outlast your suit. A low-profile, comfortable design that never
interferes with your swim. Automatically sync with your phone to get advanced swim tracking from Swim.com.

The SELF Institute