QuietComfort Ultra Earbuds are the ultimate earbud experience. Breakthrough spatialized audio for more immersive listening makes your music feel realer than ever before - no matter the content or source. Bose Immersive Audio takes what you're hearing out of your head and places it in front of you for the most natural listening. And CustomTune technology takes it to another level by analyzing your ear's shape and adapting the sound and world-class noise cancellation so everything hits just as it should. The comfort is shaped to you, too. You get nine combinations of eartip and stability band sizes to find the best fit.