How do the QuietComfort Ultra Earbuds differ from the earlier QuietComfort Earbuds II?

The Ultra adds Immersive Audio spatial mode and keeps the same CustomTune calibration and fit kit. Noise cancellation and fit are close between the two, so the spatial mode is the main reason to pick the Ultra.

How long does the battery last?

Bose rates them for roughly six hours per charge in standard mode and about four with Immersive Audio on, with extra charges from the case. Expect shorter runs at high volume.

Do they work with iPhone and Android?

Yes. They connect over Bluetooth to both, and the Bose app gives EQ, mode controls and firmware updates on either platform. Some features need the app.

Can I use one earbud at a time?

Yes, either earbud can be used alone for calls and audio. Noise cancellation and Immersive Audio still work in single-bud mode.

What comes in the box?

The earbuds, a charging case, a USB-C cable and a fit kit with stability bands and ear tips in several sizes. No wall charger is included.

Are they good for running and workouts?

They are not officially sweatproof for heavy training, but the stability bands hold them well for gym use and light runs. For swimming or downpours, pick a sport model with a higher water rating.