Inside the Charge 3 are an accelerometer, gyroscope, optical heart rate monitor, and an SpO2 sensor for tracking blood oxygen levels. The Charge 3 is the third Fitbit device to include an SpO2 sensor, following in the footsteps of both the Fitbit Ionic and the Versa smartwatches. However, currently the SpO2 monitor lies dormant inside all of these devices as Fitbit hasn't made use of it yet.
If you wear the Q Explorist close to your hand, its case size and protruding center button can activate when you bend your wrist back, or if you’re wearing thicker gloves. The worst that happens is that Google Assistant is activated, and it either does nothing or tries to ask Google whatever nonsense the microphone picks up inadvertently. That can be annoying, and may cause you to size your watch band a bit larger, so the watch sits up your arm a bit more, clear of your wrist joint. Sadly, Wear OS lacks a “left-handed mode” to allow for turning the watch and its gestures the other direction.
On-Screen Workouts/ Connected GPS/ Bluetooth/ Smartphone Notifications/ 4 Day Battery Life/ Heart Rate Tracking/ 15 Exercise Modes/ SmartTrack/ All-Day Activity/ Female Health/ Sleep Tracking And Stages/ Cardio Fitness Level/ 3-Axis Accelerometer And Gyroscope/ Optical Heart Rate Monitor/ Color LCD Touchscreen Display/ Water Resistant To 50 Meters/ Grey And Silver Aluminum Finish
A smartwatch is a wearable computer in the form of a wristwatch; modern smartwatches provide a local touchscreen interface for daily use, while an associated smartphone app provides for management and telemetry (such as long-term biomonitoring). While early models could perform basic tasks, such as calculations, digital time telling, translations, and game-playing, 2010s smartwatches have more general functionality closer to smartphones, including mobile apps, a mobile operating system and Bluetooth connectivity. Some smartwatches function as portable media players, with FM radio and playback of digital audio and video files via a Bluetooth or USB headset. Some models, called 'watch phones' (or vice versa), have complete functionality of a typical smartphone using LTE technology.[1][2][3]

The first digital watch, which debuted in 1972, was the Pulsar manufactured by Hamilton Watch Company. "Pulsar" became a brand name which would later be acquired by Seiko in 1978. In 1982, a Pulsar watch (NL C01) was released which could store 24 digits, making it most likely the first watch with user-programmable memory, or "memorybank" watch.[9] With the introduction of personal computers in the 1980s, Seiko began to develop computers in the form of watches. The Data 2000 watch (1983) came with an external keyboard for data-entry. Data was synced from the keyboard to the watch via electro-magnetic coupling (wireless docking). The name comes from its ability to store 2000 characters. The D409 was the first Seiko model with on-board data entry (via a miniature keyboard) and featured a dot matrix display.[10] Its memory was tiny, at only 112 digits.[9] It was released in 1984, in gold, silver and black.[11] These models were followed by many others by Seiko during the 1980s, most notably the "RC Series": During the 1980s, Casio began to market a successful line of "computer watches", in addition to its calculator watches. Most notable was the Casio data bank series. Novelty "game watches", such as the Nelsonic game watches, were also produced by Casio and other companies.[citation needed]

Waterproof to 165 feet, the Versa handles swimming as well as any other exercise, with the screen surprisingly visible underwater. As is standard with many other non-smartwatch Fitbit models, heart rate tracking is built in, which allows for detailed sleep tracking. There’s no GPS, though — if you want to track your running route, you’ll need to carry your phone or pay the extra for the Ionic model.
Fitbit's Versa is a sleek, stylish smartwatch that works with both iOS and Android and costs less than $200, which makes it the best value smartwatch you can buy. The watch lasts four days on a charge, offers female health-tracking, advanced sleep-tracking and an app store with popular apps such as Starbucks and Pandora. You can even store music offline to listen to while you work out.