Samsung Electronics Galaxy Watch 4 40mm Smartwatch with ECG Monitor Tracker for Health Fitness Running Sleep Cycles GPS Fall Detection Bluetooth US Version - (Black) (Renewed)

Key Specifications

Product Dimensions
1.59 x 1.55 x 0.39 inches
Item Weight
0.8 ounces
Shape
Heart,Irregular
Screen Size
1.2 Inches
GPS
True
Battery Cell Composition
Lithium Ion

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Samsung
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1349 reviews
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Samsung Electronics Galaxy Watch 4 40mm Smartwatch with ECG Monitor Tracker for Health Fitness Running Sleep Cycles GPS Fall Detection Bluetooth US Version - (Black) (Renewed)

The Samsung Galaxy Watch 4 is a mid‑ to high‑end smartwatch by Samsung, designed to offer a robust mix of health, fitness, and smartwatch‑style features, all wrapped into a compact 40 mm form factor. It runs on Wear OS (with Samsung’s One UI Watch interface) and aims to deliver not only basic activity tracking (steps, workouts, sleep), but also more advanced health metrics — body composition, ECG, blood pressure estimation, blood oxygen, and comprehensive sleep analysis.

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Key Features

Get Ready To Crush Your Wellness Goals With Body Readings Right On Your Wrist
Better Sleep Starts Here: Wake Up Feeling Refreshed And Recharged With Advanced Sleep Tracking; When You Go To Bed, Your Galaxy Watch4 Sleep Tracker Starts Monitoring Your Sleep And Spo2 Levels Continuously
Be Smart About Your Heart: Take Care Of Your Heart With Accurate Ecg Monitoring And Keep An Eye On Possible Atrial Fibrillation, A Common Form Of Irregular Heart Rhythm; Share Personalized Readings With Your Doctor Using The Samsung Health Monitor App On Your Compatible Galaxy Phone
Make Every Workout Count: Get The Most Out Of Every Exercise Session With Advanced Workout Tracking That Recognizes 6 Popular Activities, From Running To Rowing To Swimming, Automatically In Just 3 Minutes; Stay Motivated By Connecting To Live Coaching Sessions Via Your Smartphone Or To Dynamic Group Challenges With Your Friends
- This pre-owned product has been professionally inspected, tested and cleaned by Amazon-qualified suppliers.

The Samsung Galaxy Watch 4 is a mid‑ to high‑end smartwatch by Samsung, designed to offer a robust mix of health, fitness, and smartwatch‑style features, all wrapped into a compact 40 mm form factor. It runs on Wear OS (with Samsung’s One UI Watch interface) and aims to deliver not only basic activity tracking (steps, workouts, sleep), but also more advanced health metrics — body composition, ECG, blood pressure estimation, blood oxygen, and comprehensive sleep analysis.

Key Considerations

1

Health and Sensor Accuracy — How reliable are the sensors (heart rate, ECG, blood pressure, blood oxygen, body composition)?

2

Fitness & Daily Activity Tracking — Whether it accurately tracks workouts, steps, sleep, and overall activity; and whether those features meet your fitness goals.

3

Compatibility & Software Ecosystem — Whether Wear OS + Samsung’s software works smoothly with your phone, and whether apps/features are supported in your region.

4

Usability and Comfort — Size, weight, display quality, battery life, and how comfortable it is for everyday wear.

5

Long‑Term Support & Updates — Whether the watch will get software updates and maintain compatibility over time (important for Wear OS devices).

1

The Galaxy Watch 4 offers a comprehensive sensor set: via the built‑in “BioActive Sensor,” it can measure heart rate, ECG, blood pressure (after calibration), blood oxygen (SpO₂), and even body composition (body fat, muscle mass, water, BMR). That makes it a strong choice if you care about detailed health tracking — more than just steps and calories, but deeper insights into your body.

These factors represent the most critical aspects that will impact your satisfaction with this product.

Customer Reviews

Love, Love, Love
2025-12-11T19:48:50.886Z

I was worried about it being refurbished. I've had bad luck before. This watch has exceeded my expectations. Battery life is short-ish. I get about 3 days on a charge, but I use it endlessly. Constant heart monitoring, messages, music, all of it. I cannot complain at all. This is my 3rd Galaxy watch and by far is my favorite. I've had it for 2 months now and I am always finding new things it can do. Love love love!

U
Nikki Fox
Love my samsung watch
2025-12-11T19:49:00.933Z

Long battery life, no damages after being in water without waterproof mode on, all apps and buttons function well, brightness is adjustable to comfort of the eyes, its literally a phone on your wrist, fits perfect with all my outfits and I can use to track my steps along with be in the know about my health and monitor my stress levels. Wrist bands are easy to change

U
Reeces

Frequently Asked Questions

Final Verdict

The Samsung Galaxy Watch 4 (40 mm) is a feature‑rich smartwatch that effectively balances advanced health and fitness tracking, everyday smartwatch functionality, and comfortable daily wear in a compact package. If you are looking for a smartwatch to monitor your fitness, health metrics, sleep, and to integrate with your Android phone — this watch offers a strong value proposition.