It's been a good year for hearables, and another pair of coaching earphones have just show up on Kickstarter promising to do a lot for their size.
Fiil Technology claims its Carat Pro earphones are the first in-ears to accurately track stats, coach you and last for nine hours of battery. It's not the first to track from within our ear canals - we've tried some similar devices this year, including the similar Jabra Sport Pulse - but the Carat's battery life could give it the edge over rivals.
Read next: The best heart rate monitors
There are two versions of the earphones, the Carat and Carat Pro, both with real-time coaching. However it's the latter you'll probably want, as the "regular" Carat lacks the heart rate monitor, activity selection and some other features.
The Carat Pro offers HR monitoring and zones, 4GB of storage and voice search for finding songs, all missing in its sibling device. Fiil says the earphones can also track VO2, speed and distance traveled.
As for activities, you'll be able to track running, cycling, weights, yoga and more. Sadly they're only water resistant, not waterproof, so swimming isn't an option.
You can read more about the background science on the Kickstarter page, where it's creeping towards its $50,000 goal with just under 40 days to go. Fiil says the idea came to them in February of this year, and plan to ship to backers in June - making the production process shorter than most crowdfund campaigns we come across.
The standard Carat earphones have a retail price of $99, while the Pros will cost $249. There are, as usual, discounts if you decide to back them early.
How we test