Hammerhead Karoo exports standard FIT files. Download from the Hammerhead dashboard, import into MetricsOverlay.
Export: Hammerhead dashboard (dashboard.hammerhead.io) → ride → download FIT. Or sync to Strava/TrainingPeaks and export from there.
Karoo records all paired sensor data: power meter, heart rate monitor, speed sensor, cadence sensor. Plus GPS, altitude, and temperature from onboard sensors.
The Karoo has good GPS accuracy since it's mounted with clear sky view, producing clean data for the map overlay.
Same FIT format as every other device. No conversion needed.