Do I need an iPhone to use it?

Yes. The Apple Watch Series 11 pairs with an iPhone running a current version of iOS and watchOS. It does not work with Android phones.

What is the difference between the GPS and cellular models?

This is the GPS model, so it uses your iPhone's connection for calls, messages and data. The cellular version adds its own mobile connection for use without the phone.

How long does the battery last?

Apple rates it for roughly a full day of normal use, and it needs charging nightly. Heavy workouts and always-on display use shorten that.

Is the 42mm case a good size?

The 42mm case is the smaller of the two sizes and suits most wrists, including smaller ones. It is lighter than the larger case and easier to wear overnight for sleep tracking.

The watch comes with a band and a magnetic charging cable. A power adapter is not included, so you use an existing USB-C charger.

Does it track sleep and blood oxygen?

Yes. It tracks sleep stages and blood oxygen, along with heart rate, workouts and activity rings. Some health features depend on your region and iPhone model.