What stays the same
Fourth Frontier
Last Update 20 hours ago
- Every metric. Heart rate, HRV, strain, breathing rate, body shock, step cadence, calories, stress, training load and sleep staging all work the same way, derived from the ECG signal on both devices.
- Frontier Premium. Identical entitlements on both devices; an existing subscription carries across.
- The same app, worn the same way, on the chest.
- IP67 — the X2 is already IP67-rated, so this is unchanged, not an upgrade.
- Third-party connectivity. Bluetooth Low Energy to compatible watches, bike computers and apps. Neither supports ANT+.