Apple Watch Series 9 | 41mm :

2x brighter display
A brilliant breakthrough.
The advanced display system in Series 9 boosts the maximum brightness up to 2,000 nits — double Series 8 — so it’s easier to read in full sun. It’s also better in low‑light situations, like a cinema, because it dims to just 1 nit.

Custom Apple silicon makes Apple Watch Series 9 more capable, intuitive and faster. The new dual-core CPU has 5.6 billion transistors — 60 per cent more than the S8 chip. A new four-core Neural Engine processes machine learning tasks up to two times faster. It enables a number of innovations, including a new gesture — double tap.
 
HomePod control. Watch takes the stage.
 A second-generation Ultra Wideband chip enables new integration with HomePod.1 When music is playing, Apple Watch Series 9 opens the Now Playing screen to let you control it. If nothing is playing, the Smart Stack will offer media suggestions to play on HomePod.2
 
The watchOS 10 update brings more to your screen than ever before. Virtually every app has been totally redesigned to give you more information at a glance. From any watch face, simply turn the Digital Crown to reveal the Smart Stack with widgets for relevant and timely information. And now with insights for mental and vision health, you can keep track of your body and mind — right from your wrist.
 
Powerful insights at a glance.
Apple Watch helps you better understand your mental and physical health. Health data is kept private and secure. 
And when you’re ready to share with a healthcare provider, friends or family members, you’re in control.