Thursday, May 23, 2024

EFO-S Black K5 Review

Exercise is crucial when it comes to maintaining a healthy lifestyle. Not only is it an effective way of losing weight, but it also significantly decreases the risk of cardiovascular disease. All in all, it’s something that’s worth incorporating into your everyday life. As beneficial as it might be however, finding the right motivation can be challenging- who doesn’t want to just lounge on the sofa and watch TV?

Fortunately, for those of us who may be struggling with this issue, there are a variety of gadgets that can help. For instance, let’s talk about fitness trackers. Small and intelligent, these devices can be used to monitor a number of things such calories burnt, distance travelled, sleep patterns, heart rate, etc., all of which can then be used to keep track of your exercise progress.

How do fitness trackers help when it comes to staying fit? By providing valuable data (e.g. steps taken, distance covered, calories burnt, heart rate, etc.), these gadgets you to visually see your progress. Whether you’re trying to lose weight, or maintain a certain level of physical activity, they can be incredibly helpful when it comes to attaining your goal. With the feedback that you’re given, it’s likely that you’ll feel more motivated to continue with your routine.

As you can probably expect, there are a variety of different fitness trackers out there on the market. For instance, you’ve probably heard of the Fitbit or the Apple Watch- both manufactured by prominent companies, they’ve each got their own respectable fanbase. In addition to those, there’s also the ones made by companies such as Nokia, Garmin, Xiaomi, Misfit, and more.

On this page, we’ll be taking a look at one of the lesser known fitness trackers on the market- the EFO-S Black K5 by the EFOSHM Company. How does it hold up against some of the more well-known brands? Is it worth buying? Hopefully, you’ll find our below review helpful.

About the EFO-S Black K5 Fitness Tracker

A type of activity monitor, the EFO-S Black K5 is manufactured by EFOSHM, an electronics company based in Shenzhen. Relatively inexpensive (i.e. Below $20 on Amazon), especially when compared to brand names such as the Fitbit, it’s ideal for those who’d like to monitor their activity, without having the need to shell out a lot of money.

Don’t let its low cost fool you however, for it still boasts a number of functions. To be more specific, it measures three main parameters: calories burnt, distance travelled, and sleep patterns.

Calories Burnt: You can monitor you process by knowing the exact amount of calories that you’ve burnt from your physical activity.

Distance Travelled: Essentially a pedometer, the tracker shows you how many steps you’ve taken in a day.

Sleep Patterns: By wearing the tracker at night, it’s able to monitor your various sleep patterns, which you can then analyze in the morning.

Other Features of the EFO-S Black K5 Fitness Tracker

Reminder Feature: Have something that you want to do tomorrow? You can easily remind yourself of the event with the tracker’s built-in reminder feature.

Text Message Notifications: If your tracker is synced to your smart phone, you will be notified of any new text messages (both iPhone and Android devices are supported, with the exception of iOS 5 and iOS 6).

View Contacts: Given that the device is synced to your smart phone, you can easily view your contact list on the tracker’s LCD display.

Touch/Gesture Control: Easy to use, the tracker comes with a OLED display that doubles as a high sensitivity touch screen.

Sleep Mode: As mentioned earlier, you can monitor the quality of your sleep by wearing the tracker at night.

EFO-S Black K5 Fitness Tracker App

In order to sync the tracker with your smart phone, you will have to download the official app “Zeroner”, which is available for both iOS (iOS 7.0 and above) and Android devices (Android 4.3 and above).

Starting with the App

Once you’ve downloaded and opened the app, you’ll be prompted to select your gender. Next, you’ll want to input your height, weight, and age (so that it can properly calculate your statistics).

After all that, you’ll be brought to the main interface.

App Interface

Pretty straightforward, the app has four main categories at the top- “Steps”, “Calories”, “Time”, and Distance.”

Steps: Displays the amount of steps you’ve taken daily on a chart (both weekly and monthly views are available).

Calories: Self-explanatory, this sections shows how many calories you’ve burnt per day on a graph (both weekly and monthly views are available).

Time: Displays the amount of active minutes you’ve had per day on a graph (both weekly and monthly views are available).

Distance: Displays the distance that you’ve travelled on a graph (both weekly and monthly views are available).

By swiping the left hand side, you’ll bring up the menu- this is where you can access “Sports Mode”, “Device Connection”, “Device Setting”, and “Push Reminders.”

Syncing the App with Your Fitness Tracker

To sync the EFO-S Black K5 tracker with your phone, enable Bluetooth, and select “Device Connection” from the menu on the app. Within a few seconds, you should be able to see your tracker pop up on the screen- click and connect.

Changing Your Settings

There are a few settings that you can change in the “Device Setting” section, these include:

Target Setting: Want to walk x amount of steps everyday? You can set your goal here (in increments of 1000).

Sedimentary Reminder: Do you happen to sit for long periods of time? With this feature, the tracker will alert you every time you’ve been sedentary for x hours (you can customize the range). Depending on your schedule, you can have the sedimentary reminder “on” every day, or for certain days of the week.

Alarm Setting: This is fairly straightforward. Want to take a nap? Wake yourself up later by setting an alarm (though you can easily do the same on your phone).

Sleep Mode

For the “Sleep” display, select it from the dropdown menu on the top right. From there, your sleep patterns will be shown in a chart. At the bottom, you’ll be able to see how much tie you’ve spent in deep, and light sleep. In addition to that, it will display how long you were asleep for, as well as the time that you woke up.

GPS Sports

Once again, you’ll want to select “GPS Sports” from the top right dropdown menu. Once you’ve done so, you should be shown a map of your location. Once the feature has been activated, your physical activity will be displayed on the screen, along with the time, calories burnt, speed/pace, and average speed (further details are available if you swipe to the left).

EFO-S Black K5 Fitness Tracker: Pros and Cons

Now that we know more about the EFO-S Black K5 Fitness Tracker, let’s go over some of its advantages and disadvantages. Hopefully with this, you’ll be able to decide whether or not it’s worth a try.


– Inexpensive for a fitness tracker (can be purchased on Amazon for under $20); in contrast, brand names such as the Fit Bit can retail for $100+
– A great option for kids
– Comes with its own app, that can be downloaded on any Android or iOS device
– Relatively easy to set up
– Tracks your activity even when it isn’t connected to your smart phone
– Additional brackets can be purchased
– Comfortable for long wear
– Vibrates every time you receive a text or phone call
– Battery lasts anywhere from 3 to 4 days with one charge


– Instruction sheet and app is in broken English (not surprising, considering the fact that it’s made by a Chinese company)
– Some users have reported that the trackers disconnects from the app frequently
– Not waterproof
– Sleep monitoring can be buggy (i.e. doesn’t work sometimes)
– Pedometer may occasionally be inaccurate
– While the app is functional, it can use a lot of work
– Can only by synced to the “Zeroner” app (i.e. it cannot be connected to other physical activity apps)

EFO-S Black K5 Fitness Tracker: Is It Worth It?

Time for the verdict- is the EFO-S Black K5 Fitness Tracker worth it? In the end, it depends on what you’re looking for. Are you looking for something inexpensive, that might motivate your kids to do more physical activity? If so, this might be a good option. Are you looking for something simple, that can track your exercise? If so, you might want to consider the device.

On the other hand, if you’re interested in something with more features (e.g. heart rate monitor, something that can sync with other apps), you might want to go for something like the Fitbit or the Garmin Vivofit. While the EFO-S Black K5 is a decent activity tracker, it lacks many of the “cooler” functions that some of the fancier fitness trackers have.

Verdict: It depends. For some people, it’s worth it, for others, it’s not. Ultimately, it hinges on what kind of features you’re looking for in a fitness tracker. While it’s no Fitbit, the EFO-S Black K5 does get the job done.

Where Can I Buy the EFO-S Black K5 Fitness Tracker?

The easiest way to get your hand on the EFO-S Black K5 is probably through Amazon. At the time of this writing, it’s priced at $15.67.

Brooke Carter
Brooke Carter
Freelance writer who loves dogs and anything related to Japanese culture.


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