The Dura Ace R9100-P power meter is one of the best power meters out there. It offers reliable training data in a fully integrated package, and precision is amongst the best in its class. With dual-side power, a weatherproof battery and 300 hours between charges, it's a seriously good product.

Main features:

• Reliable electronics
• Strain gages developed by Shimano
• Automatic compensation from software
• Easy and fast start-up
• Weatherproof in all conditions
• Bluetooth LE and ANT+ connectivity
• Wireless update of micro-software
• Rechargeable battery integrated
• Chainrings easily interchangeable without affecting power calibration
• Compatible with direct mount Shimano brakes
• Active temperature compensation
• Battery: rechargeable lithium-ion with 300 hours autonomy
• Easy maintenance
• Great precision