The main differences between the Garmin fēnix 7X Sapphire Solar and the fēnix 7X Pro Sapphire Solar are as follows:

## Heart rate sensor
- The fēnix 7X Pro Sapphire Solar has a new, improved optical heart rate sensor (Elevate Generation 5) that provides more precise measurements and offers additional ECG capacities.

## Illumination
- The fēnix 7X Pro Sapphire Solar has improved lighting, including an integrated flashlight that increases readability in all lighting conditions.

## Skin temperature
- The fēnix 7X Pro Sapphire Solar can track changes in skin temperature during sleep, which can be useful for health data and menstruation tracking.

## Display
- The fēnix 7X Pro Sapphire Solar has a new display with a higher pixel density that consumes less energy and offers better readability, especially indoors.

## Additional functions
- The fēnix 7X Pro Sapphire Solar offers additional functions such as the Hill Score, which measures performance when running uphill, and the Endurance Score, which evaluates the ability to perform longer-term efforts in various sports.

These differences make the fēnix 7X Pro Sapphire Solar an attractive option for users looking for the latest technology and advanced health and fitness features.