The AirPods Pro are a high-end version of Apple's popular wireless earbuds. They cost $249 -- nearly $100 more than the standard model.

The new headphones boast a new design and features such as noise cancellation.

was expected to announce the new model at its annual event in October where it typically reveals new hardware products such as the iPad and MacBook Pro. But it waited to announce the Pro version of its earbuds in a press release on Monday.

Here are four things to know about the AirPods Pro:

1. Design differences

The high-end model has one major difference: silicone tips that allow for customization and better fit.

The newest AirPod model features a comfort tip.

The AirPods Pro come with three sizes of silicone tips. Interchangeable tips aren't a new feature for earbuds but they're new for Apple, which has until now only offered an all-hard-plastic earbud.

People can take a comfort test in the Control Center on their iOS device to see which size is best suited for their ears. The internal microphone listens and compares what the earbud speakers are putting out in real-time and provides feedback on whether the tips a person is wearing are the right fit. Some people may find that their right ear and left ear require different size tips.

The Pro earbuds also have a vent on the side of each piece, which continuously equalize the pressure in a user's ear, making them more comfortable to wear. Apple boasts that it will feel like there's nothing in your ears.

2. Noise cancellation

Beyond increased comfort, the silicone tips also allow for noise cancellation.

Again, not a new concept in the world of earbuds but new for Apple.

The noise cancellation capabilities are enhanced with the ability to swap out the size of the earbud tip and better fit a wearer's individual ears. The tips click into place, making them easy to change out.

Apple claims its AirPods Pro are the first in-ear headphones with active noise cancellation that continuously adapts at 200 times per second to the geometry of a wearer's ear and the fit of the ear tips.

Here's how it works: There's an outward-facing microphone on the earbud that detects external sound. The Pro then counters that external sound with equal anti-noise, so the wearer never hears the external sound. An inward-facing microphone listens for unwanted sound, which is also eliminated with anti-noise.

For those who want to still be aware of their surroundings there's also a transparency mode that allows the wearer to hear what's around them.

3. New features

The AirPods Pro are sweat and water resistant for non-water sports and exercise. They also have an expanded mesh microphone port that improves call clarity in windy situations.

One of the cool features available with the AirPods Pro is audio sharing. This feature launched with iOS 13. It allows people to watch the same movie or listen to the same song as a friend wearing another pair of AirPods in real time. (That's super useful if you forget to bring your iPad on a long flight.)

4. Be prepared to wait in line

Some stores have had such high demand that lines have formed as customers eagerly queue to get their hands on a pair of AirPods Pro.

Wow. People line up for AirPods Pro now (Grand Central Apple Store this morning for the launch) pic.twitter.com/2I4SRB3nyg — Samantha Murphy Kelly (@HeySamantha) October 30, 2019

While long lines for new iPhones are the norm, the lines seen at some Apple locations on Wednesday show there's clearly demand for the launch of even the smallest Apple product.