Apple Watch Series 6 puts an emphasis on tracking blood oxygen levels.

In case one new Apple Watch wasn't enough for you, Apple unveiled twoat its product event on Tuesday held via livestream.

In addition to the Apple Watch Series 6, the company also introduced the Apple Watch SE — a new budget friendly option. Both watches are currently on pre-order with full availability on September 18.

If you're wondering what the difference is between the two, let's break it down.

Apple Watch Series 6

Aside from a few new colors, including a new Product Red model and a new blue option, the Series 6 looks identical to its predecessor. But it does pack a couple of new features under the hood including an SpO2 sensor to monitor blood oxygen levels.

The Series 6 watch comes in new colors. Credit: apple SEE ALSO: Apple unveils eighth-generation iPad and new iPad Air

Let's start with its aesthetic: The Series 6 has a square, aluminum case with rounded edges and an OLED display. The side of the case is home to the digital crown, which is used for navigation and to take ECG readings. As for accessories, Apple also introduced three new watch bands that are free of any clasps or buckles.

As for its processor, the new Watch is powered by the S6 chipset — a dual-core processor that's up to 20 percent faster than its predecessor. Battery life remains the same as the last version, at 18 hours, but the Series 6 can charge up to 80 percent in one hour.

The Series 6 also includes an always-on display feature that Apple says is 2.5x brighter than the last-generation model. Additionally, the always-on altimeter feature also tracks elevation throughout the day which you can now see in real time as a watch face complication.

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Via Giphy

But unlike the Series 5, the Series 6 comes with an SpO2 sensor to help track blood oxygen levels. On the back of the watch are a mix of infrared LEDs that are used to measure the amount of light reflected back from the wrist.

Measurements only take about 15 seconds, and all the data is saved to the Health app with the ability to look back at a history of measurements. Additionally, the watch also monitors levels throughout the night while you're asleep.

However, unlike the ECG monitor, it's important to note Apple has yet to receive FDA clearance on the feature. So, it's classified as a "wellness" feature, for you to monitor levels, rather than as a medical device.

As for pricing, the Series 6 starts at $399 for the GPS model but runs to $499 if you want LTE connectivity.

Apple Watch SE

The Apple Watch SE is certainly the more affordable option if you're looking to invest in one of these smartwatches.

On the outside, the SE has the same design as the Series 6 and borrows some features including the always-on altimeter, fall detection, Emergency SOS (with international emergency calling), and a few others.

You know, for those who don't want to spend over $400 on an Apple Watch. Credit: apple

But with that lower price point, you're losing out on other features like the SPO2 sensor, always-on display and ECG sensor. Additionally, it uses last year's S5 chipset but it'll still ship with WatchOS 7 out of the box.

As for price and availability, the Apple Watch SE starts at $279 for the GPS model and $329 for the cellular version.