The Bose QuietComfort 45 Bluetooth Noise Canceling Headphones are a pair of over-ear wireless headphones that offer excellent noise cancellation, comfort and sound quality. They are the successor to the popular Bose QuietComfort 35 II, and they have some improvements and new features.

## Design and comfort
The design of the Bose QuietComfort 45 is very similar to the previous model, with a simple and elegant look that comes in black or off-white. The ear cups are large and plush, and the headband is cushioned and adjustable. The headphones are very lightweight (240g) and fit snugly on the head without causing much pressure or fatigue. The headphones have physical buttons for controlling playback, volume, noise cancellation modes and voice assistants. They also have a 2.5mm jack for wired listening and a USB-C port for charging.

## Noise cancellation and sound quality
The noise cancellation of the Bose QuietComfort 45 is outstanding, and arguably the best in the market. The headphones have two modes: Quiet and Aware. The Quiet mode blocks out almost all external sounds, from low-frequency rumbles to high-frequency chatter. The Aware mode lets in some ambient sounds, so you can hear your surroundings or have a conversation without taking off the headphones. The noise cancellation can be switched with a button on the left ear cup, or through the Bose Music app.

The sound quality of the Bose QuietComfort 45 is also very good, but not as accurate or detailed as some other models. The headphones have a sculpted sound signature, with rich bass, clear mids and crisp highs. The bass is not overpowering, but it adds some warmth and punch to the music. The mids are well-balanced, with good vocal clarity and presence. The highs are bright and detailed, but not harsh or sibilant. The soundstage is decent, but not very wide or immersive. The headphones support SBC and AAC codecs, but not aptX or LDAC.

## Battery life and other features
The battery life of the Bose QuietComfort 45 is impressive, with up to 24 hours of wireless playback with noise cancellation on. The headphones also support fast charging, with 15 minutes of charge giving 3 hours of playtime. The headphones have a built-in microphone that works well for phone calls and voice assistants. The microphone picks up your voice clearly and reduces background noise effectively. The headphones also have multipoint connectivity, which allows you to pair them with two devices at the same time and switch between them easily.

## Conclusion
The Bose QuietComfort 45 Bluetooth Noise Canceling Headphones are a great choice for anyone who values noise cancellation, comfort and ease of use. They are not the most affordable or feature-rich headphones, but they deliver on their core functions very well. They are ideal for travelers, commuters, workers or anyone who wants to enjoy their music in peace.